Lemmatization

Lemmatization involves the reduction of corpus words to their respective headwords (i.e. lemmas). In the linguistic dictionaries that we may consult, every entry corresponds to a lemma that - generally - defines a set of words with the same lexical root (or lexeme) and that belongs to the same grammatical category (verb, adjective, etc.).

As a rule, lemmatization entails that verb forms are taken back to the base form, nouns to the singular form, and so on.

For example, the inflected forms "speaks" and "speaking", resulting from a combination of a sole root with two different suffixes (<-s> and <-ing>), are brought back to the same lemma "speak". There are, however, some cases in which the lemmatization doesn't observe the rule of the common root; particularly in the case of many irregular verbs.

During the corpus importation phase, T-LAB carries out a specific kind of automatic lemmatization, that follows the logic of the following "tree".

Obviously, the reference dictionary is the one implemented in T-LAB.

The abbreviations of the four-categories are used in many tables, always in the "INF" column (or field).

In particular, the "DIS" category ("to distinguish") means that T-LAB does not apply the standard lemmatization, in order to avoid annulling the significant meanings among the different forms.