The module determines the lemma(s) and inflection(s) returned by supplying either a Universal Dependencies or Penn Treebank tag. Not all of the tags in these sets are used by LemmInflect. The following is a list of the various types and tags used...
upos = 'ADJ' * JJ Adjective * JJR Adjective, comparative * JJS Adjective, superlative upos = 'ADV' * RB Adverb * RBR Adverb, comparative * RBS Adverb, superlative upos = 'NOUN' * NN Noun, singular or mass * NNS Noun, plural * upos = 'PROPN' * NNP Proper noun, singular or mass * NNPS Proper noun, plural upos = 'VERB', 'AUX' * VB Verb, base form * VBD Verb, past tense * VBG Verb, gerund or present participle * VBN Verb, past participle * VBP Verb, non-3rd person singular present * VBZ Verb, 3rd person singular present * MD Modal
A Note on AUX and MODAL types
Verbs can be further subdivided into auxiliary verbs, some of which can be modal auxiliary verbs
The Penn Treebank tags have 'MD' but no 'AUX' category
UPOS tags have 'AUX' but no 'MODAL'
The SPECIALIST Lexicon's "category" system has both
To make things more confusing, taggers will sometimes label these as verbs. Luckily the list of these words is small. * AUX verbs: have(has, had), be(is, was, been), do(does, did) * MODAL verbs: can, could, may, might, will, would, shall, should, must, ought, dare