Linguistic Modeling for Multilingual Machine Translation

8.1. THEMATIC ROLES 77
In addition to the inuence of the predicate on the morpho-syntactic properties
of the arguments, arguments may determine the morpho-syntactic properties
of the head: In the Section 5.3.3 I showed how concepts of the TL are reconstructed
out of the notional domain through a semantic classication.
The A-Structure of a concept equally inuences the choice of the appropriate
concept. This is illustrated through (35). If we add the agent to the English
sentence and inverse the direction of translation, the adjectival realization
of the German predicate is no longer possible, as the adjective expresses the
agent only with great diculties:
thematic roles
(117) a. the man who can be blackmailed by his wife
b. German:
?? der
the
von/durch
by
seiner
his
Frau
wife
erpressbare Mann
blackmailable man
c. der Mann, der von seiner Frau erpret werden kan
the man who by his wife blackmailed be can
8.1 Thematic Roles
Although our approach is similar to that suggested in [Steiner et al.88], our set
of thematic roles is much more limited. [Steiner et al.88] use the thematic roles
for two dierent purposes, (i) the reading distinction of, for example, mental
and action verbs through the use of dierent sets of thematic roles and (ii) the
correct linking of argument constituents to the argument slot in the TL, independent
of the linking in the SL (cf. the examples of argument switching). For
various reasons I use the thematic roles only for the latter purpose, so that the
system of thematic roles has to serve onlythisaim 1 . In our system role=agent,
role=theme and role=goal are the most important thematic roles to which are
added role=location, role=provenance and role=direction for movement
verbs and role=class for copulative-like constructions 2 . The set of thematic
roles of the predicate represents the coupling of the participants to the participants
of a prototypical situation, where the theme is the entity the event is
1 The reasons for working with a limited set of thematic roles are the following. (i) with
a larger number of possible roles, the consistency between coders is very low. (ii) A large
number of thematic roles mayintroduce ambiguities which cannot be motivated on monolingual
grounds. (iii) The control of the readings in transfer (e.g. action verbs are translated as
action verbs) does not work if the arguments are not realized, so that the readings are distinguished
instead by the semantic coding of the predicate itself as 'action', 'mental process'
or other.
2 role is used also to specify the syntactic role of nodes (non-argument roles) as there
are: role=funct for every functional category, role=mod for every modier and role=pred
for predicative nouns in support verb constructions.