Verb-Noun Combinations in Machine Translation

2a. Syntactical Differentiation

The use of roles in establishing a correct picture of syntactical relations in the source language (SL) clearly has implications for translation to the target language (TL). To stay with the last example: accurate identification of the syntactical function of `auf' will trigger the transfer (translation rule) stipulating that `bestehen' means `insist' when followed by a dependent POBJ with `auf'. Verb roles are the life-blood of machine translation because so much semantic differentiation depends on them. Again, `bestehen' provides a good example:

1. `bestehen' + DOBJ = `pass'
2. `bestehen' + POBJ with `in' = consist
3. `bestehen' + POBJ with `aus' = consist
4. `bestehen' + POBJ with `auf' = insist

2b. Semantic Differentiation

The reader will already be thinking up examples of how the kind of rules for differentiation described above can misfire. What happens, for instance, when bets are being taken in the schoolyard on who is going to win the lunch-break punch-up? "`Ich setze 20 Mark auf Peter', sagte Maria, `weil er so schöne Muskeln hat'". Here the translation is clearly `bet', not `count'. In the case of `tragen', it is even easier to find ambiguous sentences of the kind that make MT researchers despair. Thus `Er trug die Hose ins Badezimmer' is clearly not `He wore his trousers into the bathroom': here additional information on the existence of an accusative POBJ would be required. But by and large the verb-role functionality makes it possible for MT to gain some sort of a picture of the verb from its immediate syntactical and semantic context, thus paving the way for a reasonable translation in most cases.

2c. Differentiation by means of Subject-area

2d. Precise Differentiation by means of Canonical Form

3a. MAPPING Transformation

`erinnern' --> `remember'
TEST on presence of DOBJ reflexive
MAP POBJ with `an' to DOBJ
DELETE reflexive pronoun

We will then get `I remember my first love'. Mapping from one role to another is especially helpful with axiomatic expressions, as in the case of the sentence `Maria lebt immer in den Tag hinein'. This might be rendered in English as `Maria takes each day as it comes'. To achieve this, the transfer entry `hineinleben'--> `take' requires the stipulation that the POBJ be replaced by a DOBJ. The transformation of the definite article into the indefinite pronoun `each' is however not possible, as a grammatical case can be transformed but not its pronominal or determiner constituents. But we would still get `Maria always takes the day as it comes', which is close, if not perfect.

3b. DELETE Transformation

`ziehen' --> `go away'
TEST on presence of DOBJ `Leine'
DELETE DOBJ `Leine'

3c. ADD Transformation

`fliegen' --> `be'
TEST on presence of POBJ introduced by `aus'
MAP POBJ with `aus' to POBJ with `out of'
ADD participial predicative adjective `thrown'

With any luck, `vor zwei Jahren flog er aus der Firma' will then correctly be translated as `two years ago he was thrown out of the firm'.

Testing on the existence of POBJ `aus' however can be problematic. `Der Pilot flog aus zeitlichen Gründen über Paris statt über Calais' will then be mistranslated as `the pilot was thrown out of reasons of time above Paris instead of Calais'. The problem in this example sentence is that `aus' is an adverbial marker: it does not introduce a POBJ. Even if we have another transfer entry in the lexicon for `fliegen' stipulating that it means `to fly' when used with `über', the MT system will typically still opt for the mistranslation as `aus' is positioned closer to `flog' than `über'. The definition of means of differentiation can be not exclusive enough. On the other hand it can also be too exclusive, as is exemplified by the fact that `fliegen' can mean `to be thrown out' in contexts where there is no contiguous `aus', albeit in colloquial contexts (e.g. `Du arbeitest, oder du fliegst!'): in other words, `aus' is not an indispensable semantic marker for the `be + thrown out' rendering.

3d. Combining MAPPING, DELETE and ADD Transformations

`antrinken' --> `get'
TEST on presence of reflexive accusative
TEST on presence of DOBJ `Rausch'
DELETE DOBJ `Rausch'
DELETE reflexive accusative ADD participial adjective `drunk'>

This is a highly complex piece of coding, involving considerable lexical and syntactical rearrangement of the constituents in which both additions and deletions play their part.

German abounds with semi-idiomatic expressions in which verbs such as `bringen', `setzen', `ziehen', `stellen' and `kommen' are used together with prepositional phrases - frequently nominalizations - to form a fixed unit. Examples are:

bringen: `in Gefahr bringen', `in Umlauf bringen', `zur Anwendung bringen';
setzen: `in Beziehung setzen', `außer Kraft setzen', `in Umlauf setzen';
ziehen: `aus dem Verkehr ziehen', `in Betracht ziehen';
stellen: `in Rechnung stellen', `zur Verfügung stellen', `in Frage stellen';
kommen: `zum Vorschein kommen', `in Frage kommen'

In the case of these expressions, the verb has, semantically speaking, an ancillary function: the main semantic thrust lies with the POBJ. In English, such combinations of semantically weak verbs and POBJ are less frequent, and usually the German combinations such as those above will be translated into English by one verb. Thus:

in Gefahr bringen = endanger
in Umlauf bringen = circulate
in Betracht ziehen = consider
in Frage stellen = question
zum Vorschein kommen = appear

As far as machine translation is concerned, providing the correct rendering is not as easy as it might first appear to be.

4a. Testing on the Noun within the POBJ

4b. Testing on the POBJ by Coding it as an ADV

`bringen' --> `find out'
TEST on presence of ADV `in Erfahrung'
DELETE ADV `in Erfahrung'

So far so good. However, the POBJ combinations used with semantically weak verbs are not always unmodifiable syntactico-semantic units. One can conceive of adjectives being inserted between the preposition and the following noun. `Er hat es in schmerzhafte Erfahrung gebracht' is a rather fanciful example; but `das Feuer hat den geliebten Firmenchef in höchste Gefahr gebracht' is more realistic. Indeed whole participial structures can be inserted, as in `das Feuer hat den geliebten Firmenchef in höchste, die ganze Mannschaft in Angst und Schrecken versetzende Gefahr gebracht', which is somewhat Kleistian, but by no means absurd. In such cases, testing on the presence of the ADV `in Gefahr', `in Erfahrung' etc. will not work, as the system's understanding of these adverbs does not extend to modified forms.

4c. Single or Multi-word Translations?

4d. Problems attendant on Transformation

One might argue that a more sensible way of handling `in Betrieb nehmen' or `in Freiheit setzen' would be simply to stipulate the desired translations for the adverbs `in Betrieb' and `in Freiheit' in the adverb transfer lexicon, thus obviating the need for delete and add transformations in the verb transfer lexicon. But the standard adverbial translation of `in Betrieb' would surely be `in operation', not `into operation'. And `in Freiheit' cannot always be translated as `free' (`Wir leben in Freiheit' = `We live in freedom').

4e. `Zur Verfügung stellen' and what needs to be made available...

4ei: `Zur Verfügung stellen' = `provide'

1. DELETE `zur Verfügung'.
2. MAP IOBJ (case dative) to DOBJ.
3. MAP DOBJ to POBJ with `with'.

This piece of coding is certainly effective, even when other adverbs are inserted, such as in the sentence `Wir stellen Ihnen das Programm sofort zur Verfügung'. But problems arise with variant sentences such as `Wir stellen Ihnen das Programm zur sofortigen Verfügung', a businessspeak not uncommon in Germany. The possibility of interpolating adjectives into the adverbial phrase demonstrates that it is not a fixed syntactico-semantic unit. Treating it as a set canonical form is restrictive. The only potential solution here would be as follows. Firstly, we would need to be able to test both on the presence of the preposition `zu' and on the presence of a following noun with the canonical form `Verfügung'. Now comes the difficulty: the prepositional phrase `zu + Verfügung' cannot be deleted as a node without losing the `sofortig. A logarithm would be required according to which only the preposition and its noun object would be deleted, the interpolated modifier being preserved for translation. But of course the modifier `sofortig' would in the English translation have an adverbial function, i.e. `provided immediately'. So we need:

1. A DELETE transformation to remove the preposition and its dependent noun.
2. A MAP transformation rendering any German adjectival modifier of the dependent noun as an English adverb.
3. A MAP transformation transforming any dative IOBJ into a DOBJ.
4. Fourthly, a MAP transformation transforming any DOBJ into a POBJ with `with'.

This would produce the translation: `We provide the customers with the program immediately'. This coding should also prove effective in the case of complicated extended attributes such as `Wir stellen Ihnen das Programm zur baldmöglichsten, wenn nicht sofortigen Verfügung', since both modifiers can happily be rendered as adverbs in English. At present there is to my knowledge no commercial system which allows step 2 above, which seems to me a failing.

4ei: `Zur Verfügung stellen' = `place at the disposal'

1. DELETE `zur Verfügung'.
2. ADD `at the disposal'.
3. MAP any indirect object into a POBJ with `of'.

However, this would not produce a correct translation. Indeed the resulting translation - `We place at the disposal the program of our customers' - is disastrously misleading. The problem is that add transformations at present allow for addition to the verb, but not for addition to its direct object, which is what would be required here. A potential solution would be to transform the IOBJ into a POBJ introduced by the compound preposition `at the disposal of', which would certainly give us `We place the program at the disposal of our customers'. But we would still have the problem as to what to do when `zur Verfügung' containers a modifying adjective. In this case it would need to be inserted into `at the disposal of' as `at the immediate disposal of', but there is no way we can cater in present MT systems for the introduction of additional elements into fixed lexical forms.

4f. Participial Use

4g. Special case of `erfolgen'

In English the translation of such a structure could never be one-to-one. One would never write `The deletion is carried out with the F key', which sounds far too impersonal. Better would be `You can delete with the F key', or `To delete you use the F key', or `Use the F key to delete'. Whichever one of these we take, there is quite a bit of syntactic rearrangement going on, and this is a rearrangement of which MT is currently not capable.

For an MT system to turn `Die Löschung erfolgt über die F-Taste' into the simplest option `You delete with the F key', a number of transformations are required. First, we would have to instruct our system to turn the nominal subject of the verb `erfolgen' into a verb in the second-person, by seeking the verb from which the noun derives and then rendering it by its English equivalent. There is no system currently on the market as far as I know which allows for such a monstrous transformation. The second step would be to instruct our system not to translate `erfolgen', which we can tell the system to do, but at the risk of it then also refusing to translate any dependent adverbs. But the second step is in any case pointless without the first one, which is, as I said, not feasible in current systems. And of course it is by no means advisable to make a general rule out of this, as there are always exceptions. In an instruction manual for budding doctors, `Die Behandlung erfolgt im Krankenhaus' could not reasonably be translated as `You treat in the hospital'; better would indeed be `The treatment is carried out in the hospital'. And imagine you are a patient sitting in the doctor's surgery in Germany. You do not speak German, and have your personal machine translator with you. The doctor tells you you have a broken arm and adds `Die Behandlung erfolgt im Krankenhaus'. Your personal translator comes out with `You treat in the hospital'. No, no, you reply, I'm not the doctor, you are... A chaotic conversation ensues... So it's probably just as well that translating machines cannot transform nouns into second-person verb forms: this would be in some cases a severe distortion of sense.