Proceedings of the COLING/ACL 2006 Main Conference Poster Sessions, pages 555–562,
Sydney, July 2006. c©2006 Association for Computational Linguistics
Modeling Adjectives in Computational Relational Lexica 
 
Palmira Marrafa 
Department of Linguistics, Faculty of Arts, 
University of Lisbon and 
CLG – Group for the Computation of Lexical 
and Grammatical Knowledge,  
Center of Linguistics – University of Lisbon, 
Avenida Professor Gama Pinto, 2 
1649-003 Lisbon Portugal 
palmira.marrafa@netcabo.pt 
Sara Mendes 
CLG – Group for the Computation of Lexical 
and Grammatical Knowledge 
Center of Linguistics – University of Lisbon 
Avenida Professor Gama Pinto, 2 
1649-003 Lisbon, Portugal 
sara.mendes@clul.ul.pt 
  
Abstract 
In this paper we propose a small set of 
lexical conceptual relations which allow 
to encode adjectives in computational re-
lational lexica in a principled and inte-
grated way. Our main motivation comes 
from the fact that adjectives and certain 
classes of verbs, related in a way or an-
other with adjectives, do not have a satis-
factory representation in this kind of 
lexica. This is due to a great extent to the 
heterogeneity of their semantic and syn-
tactic properties. We sustain that such 
properties are mostly derived from the 
relations holding between adjectives and 
other POS. Accordingly, our proposal is 
mainly concerned with the specification 
of appropriate cross-POS relations to en-
code adjectives in lexica of the type con-
sidered here.  
1 Introduction 
As well known, the experiment conducted by 
George Miller on the mental lexicon properties 
in the early 80s pointed out that lexical meaning 
is derived from a set of lexical and conceptual 
relations among concepts. Subsequently, a com-
putational lexicon conceived as a semantic net-
work has been built (the Princeton WordNet 
(Miller, 1990; Fellbaum, 1998)). Given its psy-
chological plausibility and its crucial role for 
applications like machine translation, informa-
tion retrieval and language learning systems, 
among many others, this relational lexicon 
model is being extensively adopted for machine 
lexical knowledge representations, playing a 
leading role in this field.  
One of the most salient undertaking in this 
domain is EuroWordNet (Vossen, 1998), a mul-
tilingual database which stores wordnets for sev-
eral European languages that follow the same 
main lines as the Princeton WordNet (Miller, 
1990; Fellbaum, 1998) and are inter-related 
amongst them.   
EuroWordNet wordnets follow the Princeton 
WordNet model, but they are richer concerning 
both the number and the nature of conceptual 
relations.  
The work depicted here programmatically 
adopts the EuroWordNet framework. 
In general terms, it deals with the specifica-
tions for an accurate modeling of lexical knowl-
edge in a EuroWordNet wordnet-like database 
for Portuguese (WordNet.PT, henceforth), spe-
cifically focusing on the lexical semantics of 
adjectives. 
Although WordNet.PT (Marrafa, 2001; Mar-
rafa, 2002) is being developed in the general Eu-
roWordNet framework, basic research has been 
carried out on Portuguese in order to guarantee 
the WordNet.PT accuracy. This work has al-
ready led to some changes and new directions 
(cf. Marrafa et al., (2006) and Amaro et al., 
(2006), for instance).  
In this paper we propose a small set of new re-
lations which allow a strongly empirical moti-
vated encoding of the major POS in Word-
Net.PT, despite the fact that we particularly fo-
cus on adjectives. The empirical issues at stake 
are described in section 2. In section 3 we dis-
cuss the strategies adopted in previous work car-
ried out both in WordNet and EuroWordNet 
frameworks, in order to make their shortcomings 
apparent. In section 4 we present our proposal 
555
and argue for its relevance and soundness. Sec-
tion 5 presents some results concerning the en-
coding of adjectives in WordNet.PT. We con-
clude the paper with some final remarks. 
2 Empirical Issues 
Adjective semantic analysis and representation is 
far from being a trivial issue, as adjectives show 
a very particular linguistic behavior, namely in 
what concerns sense change depending on lin-
guistic context. Being so, there are several dif-
ferent typologies and classifications of adjectives 
in the literature: semantic based classifications, 
syntactic based classifications, classifications 
regarding the relation holding between the adjec-
tive and the modified noun, and so on.  
As our work on this issue progresses, it has 
become clear that only a combination of syntac-
tic and semantic criteria can offer interesting 
insights concerning adjective linguistic behavior 
and the identification of relevant common fea-
tures, which may set the basis for an accurate 
modeling of this POS in computational relational 
lexica. In this section we will briefly look at 
some of the main adjective classifications. 
Regarding the way adjectives relate to the 
noun they modify, we consider two classes: 
property ascribing adjectives (in (1)), which add 
a new restriction to the properties introduced by 
the modified noun; and reference modifying ad-
jectives (in (2)), which behave like a semantic 
operator, taking the reference of the modified 
noun as its argument1.  
 
(1) o livro azul 
     ‘the blue book’ 
(2) o diamante falso 
    ‘the fake diamond’ 
 
Adjectives like falso (fake), for instance, deal 
with concepts instead of real or referential ob-
jects, showing how a concept applies to a par-
ticular object. These adjectives constitute a 
closed class with very particular properties, 
which makes them somewhat close to semantic 
operators. In this work we will therefore focus 
on property ascribing adjectives. 
                                                          
1 This distinction between property ascribing adjectives and 
reference modifying adjectives is basically equivalent to 
the one used in the SIMPLE project (Lenci et al., 2000)  
(extensional vs. intensional adjectives, following Chier-
chia and McConnel-Ginet (1990)) to address the seman-
tics of adjectives. This distinction is also included in the 
EAGLES recommendations for a semantic typology of 
adjectives. 
Demonte (1999) classifies property ascribing 
adjectives based on their intrinsic meaning, a 
classification combining syntactic and semantic 
criteria to determine which adjectives belong to 
which class. Two main subclasses are consid-
ered: descriptive adjectives and relational adjec-
tives. Each of these classes displays specific se-
mantic and syntactic properties.  
In languages like Portuguese, descriptive ad-
jectives can occur both in attributive and predi-
cative contexts, while relational adjectives occur 
almost exclusively in attributive contexts2. Both 
prenominal and postnominal positions are possi-
ble for descriptive adjectives in attributive con-
texts. Relational adjectives, on the contrary, can 
only occur in postnominal position. Finally, de-
scriptive adjectives are gradable, i.e. they can co-
occur with degree adverbs, which is not the case 
for relational adjectives. However, these criteria 
are not always sufficient to make a clear-cut dis-
tinction between relational and descriptive adjec-
tives. Demonte (1999) proposes some additional 
criteria in order to make a more accurate distinc-
tion between these adjectives: their occurrence 
in comparative structures, and the formation of 
polarity systems. 
 
(3) a. O sabor desta laranja é mais doce do que o  
          daquela. 
         ‘this orange taste is sweeter than that one's’ 
      b. o rapaz alto / o rapaz baixo 
         ‘the tall boy / the short boy’ 
(4) a. *Este sabor é mais mineral do que aquele. 
          ‘this taste is more mineral than that one’ 
      b. o sabor mineral / *o sabor amineral 
         ‘the mineral taste / the amineral taste’ 
 
But most of all, and besides all the syntactical 
contrasts we have mentioned above, there is a 
clear contrast in the way these two adjective 
classes relate to the noun they modify. Descrip-
tive adjectives ascribe a single property, setting a 
value for an attribute, whereas relational adjec-
tives introduce a set of properties. 
 
(5) o prédio alto 
     ‘the high building’ 
 
                                                          
2 Predicative contexts with relational adjectives are gener-
ally ruled out in Portuguese. Nonetheless, some specific 
contexts, like contrastive contexts, for instance, seem to 
license predicative uses of relational adjectives: 
 
(I) As próximas eleições são autárquicas, não são 
presidenciais. 
    ‘next election will be autarchic, not presidential’ 
556
(6) a indústria alimentar 
     ‘the alimentary industry’ 
 
Looking at (5) and (6), we see that, while alto 
(high) sets the value of the height attribute of 
prédio (building) to high, alimentar (alimentary) 
does not ascribe a single property, but a set of 
properties to indústria (industry). Moreover, this 
set of properties corresponds to the main features 
describing another noun – alimento (food) in the 
example above. In fact, the way properties are 
ascribed to the modified nouns in (5) and in (6) 
are quite different. Ascribing a singular property 
usually corresponds to an incidence relation of 
this property in the nominal referent, while as-
cribing sets of properties usually entails more 
complex and diversified semantic relations.  
However, despite the relevance of the descrip-
tive/relational dichotomy, it cannot account for 
the following contrasts: 
 
(7) a. *Ele viu a Maria alta. 
          ‘He saw Mary tall’  
     b. Ele viu a Maria triste. 
        ‘He saw Mary sad’. 
 
Both alta and triste are descriptive adjectives, 
but they do not behave in the same way regard-
ing secondary predication. 
We can refine the classification, considering, 
for instance, the opposition between accidental 
properties and permanent or inherent properties 
(this distinction goes back to Milsark (1974; 
1977) and Carlson (1977)). According to this 
distinction, the property denoted by alta (tall) 
belongs to the latter class and the property de-
noted by triste (sad) to the former one. However, 
as pointed out by Marrafa (2004) and previous 
work, the characterization of adjectives on the 
basis of this dichotomy is not straightforward, 
since certain adjectives are ambiguous with re-
gard to those properties, as it is the case of triste 
(sad). In the example above triste (sad) denotes 
an accidental property, but in an expression like 
um livro triste (a sad book) it denotes a perma-
nent property. 
Intuitively, we can say that triste (sad) ex-
presses a state of tristeza (sadness), but we let 
the discussion of the status of this relation out of 
the scope of this paper. 
Nevertheless, this kind of adjectives is of 
great importance to model telic verbs. The se-
mantics of telic verbs involves a change of state 
of their theme argument, i.e. the subevent that 
closes the whole event is an atomic event, (a 
state) that affects the theme and is different from 
its initial state. As argued in Marrafa (2005) and 
previous work, by default, verbs like lavar (to 
wash) are associated to the following Lexical-
Conceptual Structure (LCS’ in Pustejovsky 
(1991)): 
 
(8) [T [P act(x,y)and ~ Q(y)],  [eQ(y)]] 
T:transition, P:process, e: event, Q: atomic event 
 
When syntactically realized, the telic subevent 
generally corresponds to an adjectival constitu-
ent, like in the example below: 
 
(9) Ele lavou a camisa bem lavada. 
      'He washed the shirt well washed' 
 
In (9) the absence of the telic expression bem 
lavada (well washed) does not induce ungram-
maticality. However, in the case of verbs like 
tornar (to make), it seems impossible to assign a 
value to Q independently of the telic expression. 
 
(10) a. Ele tornou a Maria triste. 
            ‘He made Mary sad’ 
        b. *Ele tornou a Maria. 
            'He made Mary' 
 
Along the lines of Marrafa (1993) and further 
work, verbs like tornar (to make) are assumed 
here to be LCS deficitary, the telic expression 
filling the gap of the LCS of the verb.   
As shown below, the troponyms of these verbs 
incorporate the telic state:  
 
(12) a. Ele entristeceu a Maria. 
           'He saddened Mary' 
        b. *Ele entristeceu a Maria triste. 
           'He saddened Mary sad' 
 
The grammaticality contrast above is due to 
the fact that entristecer (to sadden) incorporates 
the telic state. This justifies that this verb can be 
paraphrased by tornar triste (to make sad). 
In this section we have mainly focused on 
property ascribing adjectives. We have consid-
ered two main subclasses, descriptive and rela-
tional adjectives, briefly presenting their syntac-
tic and semantic behavior with regard to grad-
ability, formation of polarity systems and their 
occurrence in predicative and attributive (both 
pronominally and postnominally) contexts and 
comparative structures. We have also addressed 
the issue of adjective relation with the noun they 
modify. Different adjective behavior regarding 
secondary predication is also discussed and ana-
lyzed in terms of the opposition between acci-
557
dental and permanent properties. The properties 
discussed in this section should be encoded in 
computational relational lexica such as wordnets. 
3 Adjectives in WordNet and in Eu-
roWordNet 
Hyponymy is the main structuring relation both 
in WordNet and in EuroWordNet. However, the 
semantic organization of adjectives is entirely 
different from that of other POS: nothing like the 
hierarchies of hyponymic (in the semantic or-
ganization of nouns) and troponymic relations 
(in the semantic organization of verbs) is avail-
able for adjectives. Even if it is possible to find 
some small local hierarchies, hypero-
nymy/hyponymy is far from being the crucial 
semantic relation in the organization of adjec-
tives in relational lexical databases such as 
wordnets. 
However, some authors working within the 
EuroWordNet framework have reconsidered the 
possibility of encoding hyponymy for adjectives. 
Hamp and Feldweg (1998), in the development 
of GermaNet, abandon the cluster organization 
of WordNet in favor of a hierarchical structuring 
of adjectives, arguing for a uniform treatment of 
all POS. Even though taxonomic chains of adjec-
tives yield rather flat in comparison to those of 
nouns and verbs, these authors claim to derive 
more structural information from these small 
taxonomies than from clusters, as they seek to 
eliminate what they consider to be the ‘rather 
fuzzy concept of indirect antonyms’. Even 
though the concept of indirect antonymy is not 
completely clear, it is not obvious to us why this 
fact should entail that adjectives must show a 
hierarchical organization instead. 
In ItalWordNet, Alonge et al. (2000) also or-
ganize adjectives into classes sharing a su-
perordinate. These classes correspond to adjec-
tives sharing some semantic features, and are 
generally rather flat. These authors argue for the 
possibility of inferring semantic preferences and 
syntactic characteristics of adjectives found in 
the same taxonomy. The SIMPLE project ad-
dresses the semantics of adjectives in a similar 
way, identifying a set of common features rele-
vant for classifying and describing adjective be-
havior. However, as noted by Peters and Peters 
(2000), even though similarities exist “adjectives 
belonging to the same semantic class may differ 
from each other in numerous ways”, i.e. the 
classes established in this way are not homoge-
neous.   
In WordNet, descriptive and relational adjec-
tives are distinguished, first, by being encoded in 
separate files, and second, by the relations hold-
ing between synsets.  
Descriptive adjectives are organized in clus-
ters of synsets, each cluster being associated by 
semantic similarity to a focal adjective which is 
linked to a contrasting cluster through an an-
tonymy relation. Therefore, antonymy is the ba-
sic semantic relation used in WordNet to encode 
descriptive adjectives. As argued for in Miller 
(1998), this cluster organization of adjectives 
seems to mirror psychological principles. In fact, 
this organization is clearly motivated if we rec-
ognize that these adjectives main function re-
gards the expression of attributes, and that an 
important number of attributes are bipolar. 
Relational adjectives, on the other hand, do 
not have antonyms. Therefore, they cannot be 
organized in opposite clusters. As pointed out by 
Levi (1978), the intrinsic meaning of these ad-
jectives is something along the following lines: 
‘of, relating/pertaining to, associated with’ some 
noun. The way these adjectives are encoded in 
WordNet mirrors this as it links relational adjec-
tives to the nouns they relate to.  
In GermaNet a distinct treatment of relational 
and descriptive adjectives is abandoned, as the 
distinction between these two classes is consid-
ered to be ‘not at all clear’. Nonetheless, the 
WordNet strategy for distinguishing between 
different adjective classes is maintained: listing 
lexical items in different files3. 
As pointed out in the previous section, even if 
the distinction between these two classes is not 
always clear-cut, testing adjectives against the 
set of syntactic and semantic criteria presented in 
section 2 allows us to distinguish descriptive 
from relational adjectives. We consider that this 
distinction can be mirrored in the database via 
the semantic relations expressed in the network, 
adjective listing in different files not being there-
fore necessary. In order to do this we propose 
several cross-POS relations, since in the Eu-
roWordNet model, unlike what happens in 
WordNet where each POS forms a separate sys-
tem, it is possible to relate lexical items belong-
ing to different POS. Such an approach has the 
                                                          
3 GermaNet classifies the adjectives into 15 semantic 
classes, following the classes proposed by Hundsnurscher 
and Splett (1982), with some minor changes: percep-
tional, spatial, temporality-related, motion-related, mate-
rial-related, weather-related, body-related, mood-related, 
spirit-related, behaviour-related, social-related, quantity-
related, relational and general adjectives. One special 
class is added for pertainyms. 
558
advantage of coping with adjective representa-
tion in lexical semantic databases without using 
strategies external to the lexical model, such as a 
priori semantic classes or separate files corre-
sponding to different classes.  
4 Relating adjectives, nouns and verbs 
It is undeniable that important structural infor-
mation can be extracted from the hierarchical 
organization of lexical items, namely of nouns 
and verbs. However, extending wordnets to all 
the main POS involves a revision of certain 
commonly used relations and the specification of 
several cross-POS relations. 
We previously mentioned that adjectives show 
a very particular semantic organization. Thus, 
encoding adjectives in wordnets calls for the 
specification of a number of cross-POS semantic 
relations. Here we use these cross-POS semantic 
relations to mirror adjectives main features in 
wordnet-like databases, which allows us to make 
adjective classes emerge from the relations ex-
pressed in the network. 
According to the strategies discussed in Men-
des (2006), we present here the relations we ar-
gue are appropriate to encode adjectives and 
show how they conform to some complex phe-
nomena. 
4.1 Relating Adjectives and Nouns 
To put it somewhat simplistically, descriptive 
adjectives ascribe a value of an attribute to a 
noun. We link each descriptive adjective to the 
attribute it modifies via the semantic relation 
characterizes with regard to/can be character-
ized by4. Thus, instead of linking adjectives 
amongst themselves by a similarity relation, fol-
lowing what is done in WordNet, all adjectives 
modifying the same attribute are linked to the 
noun that lexicalizes this attribute. This way, and 
in combination with the antonymy relation, we 
obtain the cluster effect argued to be the basis of 
the organization of adjectives (Miller, 1998; 
Fellbaum et al, 1993), without having to encode 
it directly in the database. 
As shown by word association tests, antonymy 
is also a basic relation in the organization of de-
scriptive adjectives. Nonetheless, this relation 
does not correspond to conceptual opposition, 
which is one of the semantic relations used for 
                                                          
4 This semantic relation is very close to the is a value 
of/attributes relation used in WordNet. We have changed 
its label in order to make it more straightforward to the 
common user. 
the definition of adjective clusters. We argue 
that conceptual opposition does not have to be 
explicitly encoded in wordnets, since it is possi-
ble to infer it from the combination of synonymy 
and antonymy relations (see Mendes (2006) for 
more details). 
Concerning relational adjectives, even though 
they are also property ascribing adjectives, they 
entail more complex and diversified relations 
between the set of properties they introduce and 
the modified noun, often pointing to the denota-
tion of another noun (cf. section 2). We use the 
is related to relation to encode this. 
Therefore, the characterizes with regard 
to/can be characterized by and the antonymy 
relations, for descriptive adjectives, and the is 
related to relation for relational adjectives, al-
lows us to encode the basic features of these ad-
jectives in computational relational lexica such 
as wordnets, while making it possible to derive 
membership to these classes from the relations 
expressed in the network. 
Another issue regarding adjectives is that they 
have a rather sparse net of relations. We intro-
duce a new relation to encode salient characteris-
tics of nouns: is characteristic of/has as a char-
acteristic to be. These characteristics are often 
expressed by adjectival expressions. Although in 
terms of lexical knowledge we can discuss the 
status of this relation, it regards crucial informa-
tion for many wordnet-based applications, 
namely those using inference systems, allowing 
for richer and clearer synsets. 
Also, it may allow for deducing semantic do-
mains from the database, as it makes it possible 
to identify the typical semantic domains of ap-
plication of adjectives. Research on the classes 
and semantic domains emerging from the rela-
tions expressed in the database is still ongoing. 
Thus, the combination of these relations al-
lows us to encode a less sparse net of adjectives. 
Besides the importance of having a more dense 
net from the point of view of wordnet-based ap-
plications, as mentioned above, this is also cru-
cial with regard to relational lexica such as 
wordnets themselves, as the meaning of each 
unit is determined by the set of relations it holds 
with other units. Thus, a denser network of rela-
tions allows for richer and clearer synsets. Fig. 1 
illustrates this idea, presenting an example of the 
way adjectives are being encoded in Word-
Net.PT. 
559
Figure 1. Fragment showing relations between adjectives and nouns5 
 
4.2 Relating Adjectives and Verbs 
We also introduce new semantic relations to en-
code telic verbs in the database (on this issue see 
also Marrafa, 2005; Amaro et al., 2006).  
As shown in section 2, the facts render evident 
that the representation of LCS deficitary telic 
verbs has to include information regarding the 
telic expression. Obviously, it would not be ade-
quate to overtly include in the synset all the ex-
pressions that can integrate the predicate, among 
other reasons, because they seem to constitute an 
open set. Rather, we claim that we can capture 
the telicity of these verbs by including a new 
relation in the set of internal relations of word-
nets: the telic sub-event relation, as exemplified 
below. 
 
(13) {make} has_telic_sub-event    {state} 
        {state}   is_telic_sub-event_of{make}5 
                                                    (defeasible)6 
 
Relating make to state by means of this rela-
tion, we capture the telic properties of the verb 
and let the specific nature of the final state un-
derspecified. This way, we also account for the 
weakness of the verb selection restrictions. As 
expected, we can also use this relation to encode 
telicity in the case of the troponyms of the class 
of verbs discussed in section 2. 
                                                          
5 Word senses presented here correspond to Princeton 
WordNet synsets (2.1 version). 
6 The relation is not obligatory in this direction.  
In these cases, we use the telic sub-event rela-
tion to relate the verb to the expression corre-
sponding to the incorporated telic information: 
 
(14) {sadden} has_telic_sub-event   {sad} 
        {sad}       is_telic_sub-event of {sadden} 
                                                         (defeasable) 
 
The global solution is schematically pre-
sented below: 
 
 
 
 
 
 
 
Figure 2. Relations between adjectives and verbs 
 
As shown, the telic sub-event relation straight-
forwardly allows the encoding of lexical telicity 
in wordnets, in accordance with the empirical 
evidence. 
It should be noticed that the existing sub-event 
relation in the EuroWordNet framework is dif-
ferent from the relation proposed here. It only 
stands for lexical entailment involving temporal 
proper inclusion. Therefore, it does not account 
for the geometry of the event. On the contrary, 
the telic sub-event relation regards the atomic 
sub-event that is the ending point of the global 
event.  
{make} 
 
 
{sadden} 
is hypernym of is hypernym of 
{state} 
 
 
{sad} 
has telic sub-event 
is telic sub-event of 
has telic sub-event 
is telic sub-event of 
 
is antonym of 
(adj){young1} 
 
(adj){old1} is characteristic of characterizes with regard to  (n){age1} 
is hypernym of 
(n){kid5} 
(adj){alimentary1} 
 
 (adj){caprine1} 
(adj){creeping1} 
 
(adj){biped1, two-footed1} 
 
(adj){quadruped1, four-footed1} 
is characteristic of 
 
(n){snake1} 
(n){snail1} 
(n){slug3} 
characterizes with regard to 
(n){locomotion1} 
(n){fare1,feeding1} 
characterizes with regard to 
characterizes with regard to 
is related to 
(adj){herbivorous1} 
 
(adj){carnivorous1} 
 
is near-antonym of 
 
is characteristic of (n){ruminant1} 
is characteristic of 
(n){goat1} 
is hypernym of 
is related to 
560
5 Encoding adjectives in WordNet.PT 
As previously mentioned, the proposal presented 
in this paper is mainly concerned with the speci-
fication of appropriate cross-POS relations to 
encode adjectives in computational relational 
lexica.  
In order to test whether the set of relations 
presented here is appropriate and allows the en-
coding of adjectives in wordnet-like lexica, we 
have introduced a selection of Portuguese adjec-
tives in WordNet.PT.  
In the first phase of the WordNet.PT project 
mostly nouns were encoded in the database. 
Thus, we have mainly focused on the encoding 
of relations between adjectives and nouns7. Ta-
ble 1 presents the number of entries and relations 
specified at the present stage. 
 
total number of adjectives  1462 
synonymy relation 252 
antonymy relation 134 
near-antonymy relation 40 
is related to relation 331 
is characteristic of relation 1293 
characterizes with regard to relation 261 
total number of relations 2311 
 
Table1. Statistics concerning the encoding of 
adjectives in WordNet.PT 
 
Besides the discussion presented above, the 
implemented data, being already a representative 
sample, show that the cross-POS relations pro-
posed here effectively allow for a fine-grained 
encoding of adjectives in relational lexica (spe-
cifically in wordnet-like lexica) through the 
specification of a denser network of relations. 
6 Conclusion 
In this paper we argue that the semantics of ad-
jectives can be appropriately captured in word-
net-like lexica by means of the implementation 
of a small set of new relations, which have a 
strong linguistic motivation and preserve the co-
herence of the model. 
We focus on property ascribing adjectives and 
we distinguish between descriptive and rela-
tional adjectives. Besides the relevance of this 
dichotomy, we also address the opposition be-
tween accidental and permanent properties, as 
adjective association to certain kind of properties 
determines their syntactic and semantic behav-
                                                          
7 Nevertheless, relations between adjectives and verbs are 
already being implemented at the current stage. 
ior, namely with regard to secondary predication. 
Here, we model these distinctions in Word-
Net.PT via cross-POS relations: characterizes 
with regard to/can be characterized by to model 
descriptive adjectives introducing permanent 
properties; has_telic_subevent/is_telic_subevent 
to model descriptive adjectives associated to ac-
cidental properties; and the is related to to model 
relational adjectives. 
Moreover, we make apparent that increasing 
the expressive power of the system has an impor-
tant impact in precision concerning the specifica-
tions of all POS, mainly induced by the cross-
POS relations. 
This way, we provide a simple and integrated 
solution for a complex and heterogeneous prob-
lem. 
7 Acknowledgements 
We wish to thank Fundação para a Ciência e 
Tecnologia who has partially funded the research 
presented in this paper (grant 
SFRH/BD/8524/2002). We also have to thank 
Instituto Camões for the support it has been giv-
ing to our research in computational relational 
lexica. 
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