Restriction and Correspondence-based Translation 
Ronald M. Kaplan 
Xerox Palo Alto Research Center 
3333 Coyote Hill Road 
Palo Alto, California 94304 USA 
Kaplan.Parc@Xerox.Com 
Jiirgen Wedekind 
Institute for Natural Language Processing 
University of Stuttgart 
Azenbergstr. 12 
D-7000 Stuttgart 1, FRG 
Juergen@ims.uni-stuttgart.de 
Abstract 
Kaplan et al. (1989) present a framework 
for translation based on the description 
and correspondence concepts of Lexical- 
Functional Grammar (Kaplan and 
Bresnan, 1982). Certain phenomena, in 
particular the head-switching of adverbs 
and verbs, seem to be problematic for that 
approach. In this paper we suggest that 
these difficulties are more properly 
considered as the result of defective 
monolingual analyses. We propose a new 
description-language operator, restriction, 
to permit a succinct formal encoding of the 
informal intuition that semantic units 
sometimes correspond to subsets of 
functional information. This operator, in 
conjunction with an additional recursion 
provided by a description-by-analysis rule, 
is the basis of a more adequate account of 
head-switching that preserves the 
advantages of correspondence-based 
translation. 
1. Introduction 
Kaplan et al. (1989) present a framework for 
translation based on the description and 
correspondence concepts of Lexical-Functional 
Grammar (Kaplan and Bresnan, 1982). LFG 
formulates the syntactic dependencies and 
generalizations of natural languages in terms of 
the properties of formal structures of different 
types: ordinary phrase-structure trees represent 
the surface constituency of sentences while 
hierarchical finite functions represent their 
underlying grammatical relations. The 
structures for a particular sentence are those that 
satisfy descriptions produced from annotated 
phrase-structure rules and lexical entries. The 
description of the more abstract functional 
structure is determined by the dominance and 
precedence relations of the superficial 
constituent structure, given the assumption that 
there is a piecewise correspondence function that 
maps the nodes in the c-structure tree into the 
units of the f-structure. Kaplan (1987) and 
Halvorsen and Kaplan (1988) extend this 
structure/description/correspondence architec- 
ture to provide modular and declarative 
characterizations of the relationships between 
syntactic structures and other levels of linguistic 
representation. Kaplan et al. (1989) suggest that 
this architecture can provide a formal basis for 
specifying complex source-target translation 
relationships in a declarative fashion that builds 
on monolingual grammars and lexicons that are 
independently motivated and theoretically 
justified. In particular, the approach permits 
features from different linguistic levels to affect 
translation without requiring that reflexes of 
those disparate features appear together in an 
otherwise unmotivated transfer or interlingual 
representation. 
Kaplan et al. (1989) offer several examples 
to illustrate the effectiveness of this approach to 
translation. These examples involve changes in 
grammatical functions from source to target, 
differences in control, and differences in 
embedding (or head-switching). The Kaplan et 
al. solutions depend on monolingual 
representations of phrasal, functional, and 
semantic information related by the 
correspondences ~p and a, with translation 
193 
correspondences • and ~' mapping source to target 
structures, as shown in the configuration in (1): 
(1) 
Source " " Target 
• ' semantic structure O --------.-~ O 
°/ ~' ~° f_structur e o ~_..__.._..-------~ o 
di) 0 / ~ ~: c-structure 
These solutions utilize the formal device of 
codescription to specify the target structure 
constraints in terms of simple compositions of the 
and z' mappings with the monolingual source 
correspondences. For instance, the fact that the 
object of the German beantworten corresponds to 
the AOBJ of the French r~pondre is indicated by 
associating the following transfer equations with 
the normal monolingual lexical entry for 
beantworten: 
(2) (~ ~ PRED FN) = rdpondre 
(1; T SUBJ)= 1;( ~ SUB J) 
(~ ~ AOBJ)= ~( ~' OBJ) 
The last line asserts that the AOBJ in the target 
f-structure is the translation of the source OBJ. 
The metavariable ~ in LFG is an abbreviation 
for (1)(M(*)) and thus denotes the f-structure that 
corresponds to the mother of the beantworten 
lexical node in the German c-structure (indicated 
by *). The expression • ~ can then be seen as 
~(~(M(*))) = ~ o ~b(M(*)) and thus as incorporating 
the composition ~odp. Significantly, the M(*) 
term is also present, which means that the target 
constraints are determined in the same recursive 
analysis of the source c-structure that is used to 
derive the source f-structure description. The 
codescription device crucially involves both a 
composition of correspondences and a single 
recursive analysis of common ancestor 
structures. This contrasts with description- 
by-analysis, another technique mentioned by 
Kaplan and Halvorsen (1988) and Kaplan et aL 
(1989) for deriving descriptions of abstract 
structures. 
2. Difficulties with the 
correspondence approach 
This proposal for correspondence-based 
translation has been scrutinized by a number of 
researchers (e.g. Sadler et al., 1989, Sadler et al., 
1990, Sadler and Thompson, 1991), and several 
difficulties have been pointed out. These 
difficulties arise particularly in cases where the 
independently motivated source and target 
structures are not very closely aligned, where 
single units in a source structure map to multiple 
units in the target (so-called splitting) or where 
hierarchical relationships are interchanged in 
mapping from source to target (switching). If 
such discrepancies are both locally bounded and 
predictable, then they can in principle be handled 
by means of codescription statements involving 
the ordinary monolingual description-language 
constructs of function-application and equality. 
But even if possible, such conservative 
treatments may not permit obvious 
generalizations about the translation relation to 
be naturally expressed. Sadler et al. (1990) 
demonstrate this point by examples in which the 
translation of a lexical head differs according to 
its dependents in the source sentence (English 
commit suicide translates to French (se) suicider 
whereas commit a crime translates to commettre 
une crime). They suggest refining the basic 
correspondence approach by separating such 
idiosyncratic source-target interactions into a 
separate transfer lexicon whose stipulations will 
override (perhaps via the priority union operator) 
the generic transfer specifications that might 
still be associated with the source-language 
predicates. 
Sadler et al. (1989) and Sadler and 
Thompson (1991) focus on another case of 
structural misalignment in translation, as 
illustrated in (3): 
(3) (a) The baby just fell. 
(b) Le b~b~ vient de tomber. 
The syntactic head of the English sentence (fell) 
corresponds to the head of the French embedded 
complement (tomber), while the English adjunct 
just corresponds to the head of the French matrix. 
Other well-known contrasts show syntactic 
embeddings in English corresponding to 
sentential adjuncts in Dutch (and German): 
194 
(4) (a) John likes to swim. 
(b) Janzwemt graag. 
Kaplan et al. (1989) discussed such differences in 
embedding and offered two alternative analyses 
that rely only on codescriptive specifications. On 
one account, head-switching is accomplished by 
mapping the source S node to an f-structure that 
contains information about the central clausal 
relations but excludes adjunct information. The 
ADV node maps to an f-structure that has the 
adverb as its main predicate with the central 
clausal f-structure appearing in argument 
position. The 'just' f-structure, though not 
accessible from the S node, maps through t to the 
outermost target f-structure. This complex 
interchange is specified in the lexical entry and 
rule in (5) and is diagrammed in Figure 1 
(ignoring such details as person, number, case, 
and tense). 
(5) (a) just ADV (1` PRED)='just<(I' ARG)>' (1; 1' PRED FN)=venir 
(~ 1` XCOMP)-----~( 1' ARG) 
(b) S -~ NP (ADV) VP 
( 1` SUB J) = ~ 1` =( ~ ARG) 
In the second proposal a completely integrated 
source f-structure maps to a single integrated 
target structure. As specified by the rule (6), the 
adverb is assigned an adjunct grammatical 
function in the source and its translation includes 
the translation of the enclosing source f-structure 
as its XCOMP, as shown in Figure 2. 
(6) S --~ NP ADV VP 
( 1' SUB J) = ~ (1' ADJ) = 
1' = (~ ~ XCOMP) 
Sadler et aI. (1989) and Sadler and 
Thompson (1991) point out a significant 
inadequacy of both these arrangements. Even 
though the proper target embeddings are derived 
under both correspondence configurations, in 
neither case does the translation of the 
f-structure of the source S node include the 
translation of the adverb. This shows up as a 
problem when such examples are embedded as 
complements in larger sentences: 
(7) (a) I think that the baby just fell. 
(b) Je pense que le bdbd vient de tomber. 
To maintain modularity, the codescriptive lexical 
entry for think must provide a direct mapping to 
the French penser that is not sensitive to the 
internal structure of the complement, along the 
lines of(8): 
think V 
(1' PRED)='think<(T SUBJ)(T COMP)>' (1; T PRED FN)=penser 
('1; 1' COMP)=l;( 1' COMP) 
But then the translation f-structure constraints 
will characterize the pair of structures (9); these 
share the common tomber substructure but are 
otherwise unrelated. 
(9} fi RED 'penser<\[Je\]\[tomber\]Yq 
o.pUBJ  REo 'J 3 J 
I RED 'venir<\[tomber\])\[b~be\]'~ u.J  REO .AV COMP ~RED 'tomber~6b6\]>' I I L UBJ JJ 
Figure 1. Head-switching with inaccessible adjunct @ 
P 
~RED 'fall<Fbaby\]>j ¢ 
UBJ ~RED 'baby;\] pRED 'venir<\[tomber\]>\[b~b~\]q 
~RED' tomb~b6\]>~| ~COMP LSUBJ ~ jj 
F REO I\]> 'Just<\[fal LARG 
195 
(I) 
J. 
Figure 2. Head-switching with integrated f-structure 
The z constraints thus leave unspecified the 
relative scopes of the penser and venir predicates. 
As Sadler et al. (1989) observe, the problem is 
even worse when several adverbs appear 
together: there is no obvious way to modify 
either of the rules (hb) or (6) to account for the 
scope interactions among the adverbs, let alone 
their relations to higher predicates. 
Sadler et al. (1989) and Sadler and 
Thompson (1991) consider several ways in which 
the translation constraints might be modified to 
circumvent these difficulties yet remain faithful 
to the spirit of the correspondence-based 
approach. While each of their proposals is 
carefully worked out, they conclude (and we 
agree) that none of them is completely 
satisfactory or particularly compelling. The 
reason, we believe, is that the head-switching 
with adverbial modifiers that shows up as a 
problem in correspondence-based translation is 
actually a symptom of a more fundamental error 
in the syntactic and semantic analysis of the 
source language. In sentences with adverbial 
modifiers, the syntactic head (which controls 
subcategorization and enters into agreement 
relations) is not the same as the semantic head 
(the predicate with widest scope). Moreover, 
normal linguistic arguments would assign a flat 
f-structure to sentences with several adverbs 
while meaning relations would be represented in 
a hierarchical semantic structure. Thus on this 
view, if translation codescriptions map from the 
proper hierarchical semantic structures via ~' 
instead of from flat f-structures via ~, adverbial 
head-switching disappears as a special problem 
for correspondence-based translation. 
Sadler and Thompson (1991, footnote I) 
mention the arrangement we are proposing, and 
observe that the translation codescription 
problems may then merely be displaced to 
equivalent difficulties in characterizing the 
monolingual o instead of z: the problems may be 
moved around and renamed, but not solved. This 
may be so, but any conceptual clarification in 
such a murky domain must be regarded as an 
advance, if only because it helps to spotlight the 
issues that are relevant to a solution and to 
connect them to other related phenomena. 
Indeed, we now suggest that adverbial 
head-switching is a special case of the general 
problem of mapping flat syntactic structures to 
hierarchical semantic ones. So-called "light 
verbs", complex-predicates, and clause-union 
phenomena in many languages are similarly 
difficult to handle in LFG using only 
codescription, attribute-value function- 
application, and equality constraints (or using 
the analogous formal devices of other theories, 
such as attribute-value unification over signs or 
categories). In the next section of this paper, we 
extend LFG's f-structure description language by 
introducing a new formal operator, called 
restriction. We illustrate its properties by 
applying it to a simple light-predicate sentence in 
Urdu. In Section 4 we combine restriction with 
description-by-analysis to characterize the 
appropriate hierarchical semantic structures for 
English sentential adverbs. At the end, we 
return to the head-switching problem of 
correspondence-based translation, providing a 
simple solution in terms of the ~' correspondence. 
3. The restriction operator and 
structural misalignments 
A simple kind of syntax/semantics misalignment 
is exemplified by constructions involving 
light-verbs or complex predicates. These are 
196 
constructions formed by two or more verbs 
involving two or more semantic relations, but 
with the notable peculiarity that the complex 
behaves as a single, monoclausal syntactic unit 
according to standard tests of subcategorization 
and agreement. Butt et al. (1990) have argued 
persuasively that Urdu complex predicates are 
syntactically monoclausal and further, that the 
complex predicate cannot be formed in the 
lexicon. The details of the argument do not 
matter for present purposes, and we will simply 
accept their analysis of sentence (10a) whose 
English translation is given in (10b). The c-, f-, 
and semantic-structures, according to their 
analysis, are shown in Figure 3. 
(I0) (a) Anjum-ne diyaa Saddaf-koxat likhne. 
(b) Anjum let Saddafwrite a letter. 
The crucial feature of this analysis is that there is 
a single set of governed grammatical functions in 
the f-structure, and these are derived 
systematically from the normal 
subcategorization of the main predicate likhne 
'write'. The governable functions of diyaa when it 
stands as an independent predicate (usually 
glossed as the ditransitive predicate 'give') are 
not represented in the f-structure. The second 
obvious feature is that the flat f-structure maps 
to the hierarchical semantic structure, where the 
outer predicate has the permissive reading 
conveyed by diyaa in its light-verb sense and the 
inner proposition contains the main predicate 
and its arguments. This analysis cannot be 
formulated using standard codescription, 
function-application, and equality because there 
is no separate level in the f-structure that the 
inner semantic proposition can correspond to and 
thus no way to describe its properties. 
While there may be a technical problem in 
finding a structure that the inner proposition can 
correspond to, there is a very clear intuition 
about what parts of the f-structure carry the 
information that constrains that piece of the 
semantic structure, namely, the sub-f-structure 
obtained by eliminating the SUBJ attribute and 
value. The following diagram depicts this 
intuition: 
(11) 
I REO x-write<S,O,02>l---  ° . BEL let \] UBJ Anjum I~IARGI Anjum | BJ2 Saddaf / IARG2 ~addaf\].. / BJ I letter J / IREL write71 
I IA.G3 II ~RED x-write<S,O,02>'l L LARG2 letterJ_j 
IOBOZ Saddaf /~ 
LOBJ letter J ~"~--'~- 
In this arrangement the semantic correspondence 
o relates each level of the semantic structure to a 
unit in f-structure space, and that unit is the 
source of constraints on the properties of the 
corresponding element of the semantic structure. 
The ARG3 hierarchy in the semantic structure is 
not the image of an attribute embedding in the 
f-structure as is usually the case; rather, the 
semantic hierarchy here corresponds to a 
subsumption relation in the f-structure lattice. 
This organization of informational dependencies 
can be expressed by means of the restriction 
operator. 
Restriction is a new operator in the 
f-structure description language notated by \ and 
with the following (partial) definition: 
Figure 3. Structural correspondences for complex predicate 
AnjuL-ne ERG 
~~ RED x-write<SUBJ,OBJ,OBJ2~ ~UBJ Anjum ~BJ2 
Saddaf S ~BJ letter 
xat lik ne 
le~er-NOM write 
0 
~F~EL let \] 
| 
I ARG1 /ll , RG3 BEt L LARG2 letterJJ 
197 
(12) If f is an f-structure and a is an attribute: 
f~a = flDom(t%{a} = {<S, v> E fl s~a} 
The restriction of a given f-structure f by a 
particular attribute a is the f-structure that 
results from deleting a and its value from f. If f is 
the f-structure in (13a), then the f-structure in 
(13b) is f~SUBJ: 
~RED kicq (13) (a) f= ISUB J John I 
LOBJ balll 
(b) f\SUBJ ---- ~RED kick" l LOBJ bal II 
Restriction is a designator analogous to ordinary 
function-application in that it provides a way of 
referring to elements of f-structure space by 
virtue of their relations to other f-structures. If f 
and g are two f-structure designators and a 
denotes an attribute, then 
(14) (f a) = (g a) 
asserts that f and g both have an 
attribute a with exactly the same 
value; they may or may not have other 
attributes and values in common. 
fla=gla 
asserts that f and g have all attributes 
and values in common other than a; 
they may or may not have values for a 
and those values may or may not be 
identical. 
Thus, restriction and function-application can be 
used to impose complementary constraints on 
f-structure values. We note that restriction is 
associative and commutative in its second 
(attribute) argument, so that \[f\a\] \b = \[f\b\] \a = 
f\(ab}, and that for any f-structure f and 
attribute a it is always the case that f\a 
subsumes f (f\a V- f). 
Returning now to the Urdu example, we see 
that if the top-level f-structure (the one 
corresponding to the S node) is denoted by f, the 
subsidiary f-structure to which corresponds the 
inner proposition in (11) is the restriction off by 
SUBJ and can be referred to by the expression 
f\SUBJ. The restriction operator can be used in 
codescription statements so that exactly the 
configuration in (11) is assigned to the Urdu 
sentence. A lexical redundancy rule can be 
introduced to systematically modify the lexical 
entries for normal verbs like likhne to make them 
suitable for combination with a light-verb: 
(15) ( ~ SUBJ) --* ( T OBJ2) 
o 1' --* o\[ 1' \SUBJ\] 
This rule replaces all references to the 
grammatical function SUBJ with OBJ2, thus 
avoiding conflict with the SUBJ introduced by the 
light verb, and it replaces all occurrences of the 
term o 1' with the term o\[ 1' kSUBJ\]. This indicates 
that the main predicate provides constraints on 
the semantic structure corresponding to the 
subject-free f-structure. As a result of this rule, 
the usual equations for likhne in (16a) would give 
rise to the alternatives in (16b): 
(16) (a) (o 1' ARG1) ---- o( ~ SUBJ) 
(o1' ARG2) ---- o( ~ OBJ) 
(b) (o\[ 1'~SUBJ\] ARG1)=o( ~ OBJ2) 
(o\[ 1' ~SUBJ\] ARG2)---- o( T OBJ) 
The lexical rule would also make other minor 
adjustments to fill out the entry; the details do 
not concern us here. 
4. Restriction and adverbial 
modifiers 
Sentence with adverbial modifiers can also be 
characterized intuitively as having a fiat 
syntactic structure with hierarchical semantic 
relations, and restriction can also be used to 
describe the appropriate structural 
configurations. The adverbial examples above 
involve only single sentential adjuncts, but our 
analysis allows for any number of adverbs with 
all possible scope ambiguities, and it can easily 
be extended to handle VP modifiers as well. We 
start with a c-structure rule that assigns 
arbitrarily many adverbs to the set-value of the 
ADJ attribute, consistent with the original LFG 
account of adjuncts (Kaplan and Bresnan, 1982): 
(17) S --~ NP ADV* VP 
( I' SUB J)-- ~ ~ e (1' ADJ) 
The sentence (18a) will be assigned the 
f-structure (18b) by virtue of this rule. Our goal 
is to associate with this f-structure the 
198 
alternative semantic structures in (19). 
(18) (a) John obviously just fell. 
(b) pRED' fall<\[John\]>' \] JSUBJ ~RED 'John'\] } 
LADJ { \[obviously\] \[just\] 
(19) Ca) I EL obviously In\]l 1 
RGI FREL just ~RGI ~EL fall 
LARGI Joh 
(b) IEL just 
RGI F REL °bvi°uslyTl 
LARGI JohnlJJ 
Intuitively, the innermost proposition in both 
(19a) and (19b) is based on the f-structure 
information in (18b) ignoring the adjuncts; the 
middle proposition in (19a) is exactly what we 
would expect for a sentence that included just but 
not obviously, and the middle proposition in (19b) 
would be appropriate for a sentence containing 
only obviously. Thus the semantic structures 
again seem to correspond to subsets of f-structure 
information, and we begin by completing the 
definition of the restriction operator. In addition 
to restricting an f-structure by an attribute, as 
defined in (12), we also define the restriction of an 
f-structure by an element of an attribute's 
set-value: 
(20) If f is an f-structure and a is an attribute: 
f\<ag> = 
.f f\ a if (fa)-{g} = t 
f\ a U {'<a, (f a)-{g} > } otherwise 
The restriction of a given f-structure f by a 
particular member of an attribute a's set-value is 
the f-structure that results from deleting that 
member of the set and also deleting the attribute 
itself if the set would then be empty. The 
relationships in (21) exemplify the pattern: 
p RED 'fall<\[John\]>\] (21) f= ~UBJ ~RED 'John\] 
~DJ { \[just\] } g = \[just\] 
= pR O 'f ll<\[Joh.\]>q f \<ADJ g>  UBJ  RED 'John\] \] 
We note that set-element restriction also has 
commutative and associative properties: 
(22) \[f~<ag>\]\<ah> =\[/~.<ah>\]\<ag> 
=t\<agh> 
The restriction operator can now be used to 
describe the semantic correspondences for 
adverbial sentences. If f designates the 
f-structure in (18b) and j and o designate the 
f-structures corresponding to the adverbs just and 
obviously, then the constraints (23a,b) describe 
the outermost REL and ARG1 configuration in 
(19a) and (23c,d) describe the next level of 
semantic embedding: 
(23) (a) (OfREL)=(oo REL) 
(b) (of ARGI)----o\[f\<CADJ o>\] 
(c) (o~\<ADJo>\] REL)----(oj REL) 
(d) (o~\<CADJ o>\] ARG1) 
=o\[f\< ADJ o j> \] 
= O~ADJ\] 
The innermost proposition can be described by 
interpreting (or redundantly rewriting) a T in the 
cedescription equations in the fall lexical entry as 
o\[ ~ ~kDJ\], that is, by interpreting the a 
specifications for all basic predicates as 
characterizing the semantics of an unmodified 
f-structure. 
The restriction constraints in (23) are 
sufficient to map f-structure subsumption 
relations into the desired hierarchical semantic 
structures, but the number of such constraints 
depends on the size of the initial adjunct set; 
indeed, (23d) suggests that the size of individual 
constraints used in this construction also grows 
in proportion to the number of modifiers. 
Constraints of this general form cannot be 
produced by the normal recursive analysis of the 
c-structure because the c-structure itself, by 
linguistic argumentation, does not have the 
degree of embedding that these constraints would 
require. The restriction operator can encode the 
intuitively desirable constraints, but an 
additional recursive process is needed to generate 
those constraints. This recursion can arise from 
an explicit traversal of the f-structure in the style 
of Halvorsen's (1983) semantic interpretation 
procedure. It can also come from lexical 
expressions of inside-out functional uncertainty; 
this formal device was introduced by Kaplan 
(1988) and has been applied to problems of 
quantifier scope (Halvorsen and Kaplan, 1988) 
and anaphoric dependencies (Dalrymple, 1993). 
Here we explore only the description-by-analysis 
199 
approach, using the following analysis rule to 
generate codescriptive assertions: 
(24) For fan f-structure, g ( (f ADJ), and g a 
sentence adverb, 
of = og and 
(of ARG1) = o\[fk<ADJ g>\] 
According to this rule, a single element is chosen 
(nondeterministically) from an adjunct set to 
contribute the relation for the semantic structure 
of the enclosing f-structure, and the semantic 
structure corresponding to the f-structure 
without the chosen element becomes that 
relation's argument. One application of the rule 
givesrise to additional structures to which the 
rule might also apply, and this recursion 
generates the appropriate set of constraints. For 
example, suppose fis the f-structure in (18b) and 
the obviously f-structure o is chosen as the 
instantiation of g in the rule. This produces the 
equations (23a,b) which define the configuration 
shown in (25). The rule then matches again 
against the lower f-structure, thereby completing 
the picture (26). 
(25) 
I! RED 'fall<\[John\])' l 0 UBJ EREO 'John"J DJ {\[obviously\]\[Just\]}J I= i vi °u'''\] 
ARG 1 
ERED 'fall<CJohn\]>7 
UBJ ~RED 'John'~ m 
DJ {\[just\]} J-- 
(26) 
Ii RED 'think<>' \] 0 UBO I~RED -' John "l /'~ DO {\[obviously\]\[just\]~ 
I\[-- ~EL obviously 
pUBJ ~RED 'John\] ARGI .... FREL KbZ ~RGI 
LADJ {\[Just\]} 
pRED 'fall<\[John\]Y7 
EUBJ ERED 'John\] J 
Joh 
The alternative in which just has wide scope (the 
semantic structure (19b)) results from 
nondeterministically choosing the j f-structure 
in the first rule instantiation. We note without 
discussion that the rule in (24) is appropriate for 
sentence adverbs, which take complete 
propositions as arguments, but a different 
semantic structure is required for adverbs that 
only modify the meaning of the basic relation, 
such as the manner adverb in (27a). The 
relational embedding in (27b) gives a better 
account of the meaning of this sentence. 
(27) (a) John walked slowly. 
(b) I. s,o, ly 11 
R61 EL ~EL walk~JJ 
LARGt John 
Assuming some suitable marking of the 
differences among adverbs, perhaps based on the 
semantic typing discussed by Wedekind and 
Kaplan (1993), this structure is defined by the 
additional description-by-analysis rule (28): 
(28) For fan f-structure, gE(f ADJ), and g a VP 
adverb, 
(of REL) = og 
(of REL ARG1)= o\[f\<ADJg> REL\] 
o\[f\<ADJ g>\] \ REL = o\[f~REL\] 
5. Head-switching and translation 
The restriction operator and the 
description-by-analysis rule (24) provide an 
account of adverbial modification that is 
motivated purely on the basis of monolingual 
linguistic argumentation. The net effect, 
however, is to provide a natural hierarchical 
structure to serve as a source of codescriptive 
constraints in correspondence-based translation. 
The adjunct translation constraints for a 
sentence such as 
(29) I think that the baby just fell. 
can now be associated quite directly with the 
adverbial lexical entries using the d 
correspondence between source and target 
semantic structures. For example, the lexical 
entry for just would include the simple equations 
in (30): 
(30) (o T REL) =just 
(¢'O ~ REL) = venir 
200 
These involve the codescriptive composition of z' 
and o together with the ~b and M that are implicit 
in ~. Along with all the other constraints from 
the lexicon, grammar, and description- 
by-analysis rules, these define the translation 
configuration outlined in Figure 4. The 
restriction f-structure that the fa\]\] semantic 
substructure corresponds to is not shown in the 
figure, but as we have seen, it is crucial to the 
declarative, order-free construction of the 
embedded head-switching translation. This 
arrangement shifts the translation burden for 
adverbial modifiers from the f-structure to the 
semantic structure and from the z correspondence 
to z'. However, despite its somewhat diminished 
role with respect to modifiers, the 
correspondence is still important in controlling 
the translation of simpler grammatical function 
assignments and other more superficial 
grammatical properties. 
6. Conclusion 
We have suggested in this paper that certain 
problems of correspondence-based translation, in 
particular the difficulty of adverb and verb 
interchanges, are more properly considered the 
result of defective monolingual analyses. We 
have proposed a new description-language 
operator, restriction, to permit a succinct formal 
encoding of the informal intuition that semantic 
units sometimes correspond to subsets of 
functional information. This operator, in 
conjunction with an additional recursion 
provided by a description-by-analysis rule, is the 
basis of a more adequate account of 
head-switching phenomena. 
References 
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Figure 4. Translation based on monolingual semantic embedding 
~t 
~EL think ~~~EL penser 7 IARG1 I I IARG1 
Je / / pEL just ven r 71 
__IARGZ J.... \['REL fall-\]ll IARGZ L--. r~EL to~ber'lll'~"~ o L 
O PREP penser<\[Je\]\[tomber\]>' ~RED 
'.think<\[l~\[fall\]>' I / SUBJ )RED 'Je"l 
SUBJ LPRED Je'l ' ' L~ PRED vent r<\[tombe P\] >Fb6be\] 
PRED 'fall\[baby\]' , , I '_-11 su.J lIP.go b6b l 
ISUBJ fiRED 'babyLJll COMP ,. - ~ ., ~ OMP 
IADJ \[ r4ust 1 ~ -Ill ~ ~ XCOMP IPRED 't°mber~eb6\]>'l ~ LJ J s -j ~ LSUBJ ~ j 
201 
\[Kaplan and Halvorsen, 1988\] Ronald Kaplan 
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202 
