The translation technology is based on the principles
of slot grammar, a method of describing grammatical structures originally
developed by IBM. The basic idea underlying slot grammar is that
every sentence and each of its constituents has a central element
(its head) and modifiers. For each head it can be determined what
kinds of slots there are availabe for modifiers
(fillers).
The slots can be determined by the part of speech of by the word
itself. Thus almost every noun can be modified by adjectives but
only some nouns can be modified by phrases beginning with the preposition
to, e. g.: message to the company. The slots which
are dependent on single words must be defined in the dictionary,
since otherwise source language sentences can neither be correctly
analyzed nor correctly translated.
Slots
The concept of a slot is central to the slot-grammar system.
Slot grammar is based on the premise that every word has its own
specific slots. Every meaning of a word must be considered, since
the word house, for example, has different slots as a verb
than as a noun. The concept of a slot is related to existing
concepts such as complement, object, and attribute.
The slots are filled by constituents known as fillers,
which can be individual words or even complete sentences. The German
verb schenken, for example, determines that the person
giving the present appears as the subject of the sentence,
the person receiving the present as the dative object,
and the present itself as the accusative object:
|
Er schenkt dem Kind ein Auto. |
Slots which belong
to a specific word are included in the dictionary as part of the
entry for that word. Because a word can have several slots, the
word is described as having a slot frame. The slot frame
of the verb schenken consists of subject, accusative object,
dative object.
Slots can be optional,
like the accusative and dative object in the case of schenken,
or mandatory, like the accusative object of verursachen.
Optional slots can be left empty, mandatory ones must be filled
to create a complete sentence.
Fillers
Slots can be filled by different constituent
parts of a sentence. These elements are known as fillers
and must be specified for the individual slots associated with each
word.
With a verb like schenken, the accusative and dative objects
are noun groups (constituent parts of a sentence whose head is a
noun). In contrast, the accusative-object slot of the verb forget
can be filled by clauses starting with that and by infinitive
clauses, in addition to noun groups:
|
Er hat das Prinzip vergessen. |
|
Er hat vergessen, dass das Prinzip
gilt. |
|
Er hat vergessen, das Prinzip zu
beachten. |
The way Translate operates
Translate breaks a text down into individual sentences (or, in
some cases, parts of sentences), and processes it sentence by sentence.
Each sentence is first broken down into individual words, which
are converted into the basic form and then looked up in the dictionary.
The words are assigned their grammatical properties and possible
translations. The sentence is then analyzed (or "parsed"), and split
into its constituent parts. The translation itself takes place in
two phases: the first phase involves lexical transfer, where each
word is assigned the valid translation for the specific context,
taking into account the options set by the user; the second phase
is structural transfer, which ensures correct word order in the
translation and carries out other necessary structural changes (see
also Correlating source-language and target-language
complements, Transformations).
Finally, the correct word forms are generated and the final translation
is produced.
Correlating source-language and target-language
complements
In order to translate a sentence it is necessary not only to know
the target-language words corresponding to the source-language words,
but also the respective slot frames. Default correlations have been
defined for the German and English slots (complements).
For example, a standard correlation has been defined between the
German accusative object and the direct object in English. For example:
|
begleiten |
subject |
accusative object |
|
accompany |
subject |
direct object |
But note the following
example:
|
bedürfen |
subject |
genitive object |
|
require |
subject |
direct object |
There is no default correlation defined for genitive objects.
Transformations
A German sentence and its English translation, or an English sentence
and its German translation, often differ with regard to their syntactic
structure. When Translate translates, it uses transformations
in such cases to make the required structural changes.
There are two kinds of transformations:
- Lexical transformations,
which are defined for specific lexical items. The respective transformations
are included in the Translate dictionary together with the other
information on the words or phrases concerned.
- Structural transformations, which describe general structural
differences between English and German. They are part of Translates's
transfer component.
Examples of structural transformations
Position of the verb at the end of the sentence in German subordinate
clauses compared with normal English word order:
|
English: |
It is good that he has
come. |
|
German: |
Es ist gut, dass er gekommen ist. |
The do construction in English interrogative sentences:
|
English: |
Did
you answer the letter? |
|
German: |
Beantworteten Sie den Brief? |
The do construction for negation:
|
English: |
I didn't
answer the letter. |
|
German: |
Ich beantwortete den Brief nicht. |
Preceding objects in German:
|
German: |
Diesen Brief
beantwortete ich nicht. |
|
English: |
I didn't answer this
letter. |
Constructions involving the use of modal verbs:
|
German: |
Er hatte das Buch nicht lesen
wollen. |
|
English: |
He hadn't wanted
to read the book. |
Lexical transformations
Words or constructions cannot always be translated in such a way
that the part of speech and slot frame correspond exactly. Translate
incorporates lexical transformations for handling a large number
of structural differences between German and English constructions.
Examples
Some verbs don't require an object in the source language, but
do in the target language. Many examples can be found:
|
English: |
He golfed. |
|
German: |
Er spielte Golf. |
|
English: |
I bank at Barclay's. |
|
German: |
Ich habe ein Konto bei Barclay. |
|
English: |
I inconvenienced him. |
|
German: |
Ich bereitete ihm Umstände. |
|
English: |
He hiccuped. |
|
German: |
Er hatte den Schluckauf. |
An English construction involving a predicate adjective can often
be rendered in German using a verb:
|
English: |
He is aware of the new situation. |
|
German: |
Er weiß von der neuen Situation. |
An English subject can be replaced by a dative object in German,
and the subject can become the accusative object. The word order
changes for like, but not with lack:
|
English: |
I like it that the vase is red. |
|
German: |
Es gefällt mir, dass die Vase
rot ist. |
|
English: |
I lack money. |
|
German: |
Mir fehlt Geld. |
Verbs which are causative in meaning when used transitively, such
as drop, are replaced by lassen in German, for which there
is no direct equivalent in the English sentence.
|
English: |
He dropped it. |
|
German: |
Er ließ es fallen. |
|
English: |
You should hear me out. |
|
German: |
Sie sollten mich ausreden lassen. |
Some English constructions with the infinitive are best rendered
by an adverb in German:
|
English: |
I like to read books. |
|
German: |
Ich lese gerne Bücher. |
|
English: |
She happened to find the book he
lost last week. |
|
German: |
Sie fand zufällig das Buch,
das er letzte Woche verlor. |
Some verbs in English passive constructions are rendered in German
by reflexive verbs in the active voice.
|
English: |
He said that he was injured. |
|
German: |
Er sagte, dass er sich verletzte. |
When defining words in Translate, the most common lexical transformation
can be specified, i.e. that have is translated as sein.
|
Englisch: |
She has walked to the house. |
|
Deutsch: |
Sie ist zum Haus gegangen. |
Further reading
Eberle, Kurt (2001),
"Translation mismatches in lexically driven FUDR-based MT,
Towards standardization of lexicon formalisms for MT", TALN,
Tours, Juillet 2001, pp. 267- 276.
Eberle,
Kurt (2001), "FUDR-based MT, head switching and the lexicon",
MT Summit VIII, Santiago de Compostela, 18-22 September 2001.
Lehmann, Hubert (2002):
"Integration von automatischer Übersetzung und Translation-Memorys"
(Zusammenfassung), (Präsentation),
tekom-Jahrestagung, November 2002
|