Idioms in the Rosetta Machine Translation System

This paper discusses one of the problems of machine trans].ation, n.m~mly the translation of idioms. The paper describes a solution to this problem within the theoretical framework of the Rosetta machine translation syst~n. Rosetta is an experimental trans] at]on system which uses an intermediate lard,mate and translates between Dutch, English and, in the future, Spanish. I ~nt roduet ion Idioms have been told still are a basic theoretical sttnlb-ling block in most linguistic theories. For the purposes of machine translation or, in genera], natural language processing , it is necessary to Ix~ able to deal with :idioms because there are so i~any of th~n in every language and because they are an essential part of it. ldioms occur in sentences as a number of words, possibly scattered over the sentence and possibly with sonde inflected el~nents; this ntnfl~er of words has to be interpreted as havip4~, one primitive meaning. For example, in (1) "nade", "peace" and "~.Rth" have to be interpreted idlomatically. Note that words that are part of the idJ~n are underlined. (1) lie has made his peace with his neighbour The classic example Is (2): (2) Pete kicked the bucket Literally this sentence means that Pete hit a specific vessel ~¢[th his foot. In the idiomatic reading the interpretation is that Pete died. It is impossib]e to infer this idiomatic meaning directly fron the prlm~tives "Pete", "kick", "the" and "bucket" and from the way they are eomblned. Idioms can undergo sy~itaetie transformations, but sometimes they are reluctant to do so. The passive sentence (3) has lost its idiomatic reading, while in the ~assive sentence (4) the idiomatic reading has heen retained. (3) The bucket was kicked by Pete (4) Mary's heart was broken by Pete Other examples are (5-12). In the idiomatic reading in (5) clefting with the object as focus is not allowed, while it is allowed in (6) if "Mary" is stressed. Clefting with the subject as focus in both (7) and (8) is permitted. In (9) the PP "at whose door" and in (I0) the NP "whose heart" can be subject to wh-movement. In (ii) the NP "Mary's heart" can be topicallzed (if "Mary" is stressed), but in (1.2) tbe NP "the bucket" cannot undergo this transformation without losing the idicanatic reading. Thus idioms behave syntactically like non-idiomatic structnres, although sometimes they are restricted. (5) It was the bucket that Pete Idcked (6) It was …