Using NLTK and WordNet; how do I convert simple tense verb into its present, past or past participle form?

Question

Using NLTK and WordNet, how do I convert simple tense verb into its present, past or past participle form?

For example:

I want to write a function which would give me verb in expected form as follows.

v = 'go'
present = present_tense(v)
print present # prints "going"

past = past_tense(v)
print past # prints "went"

Answer 1

I think what you're looking for is the NodeBox::Linguistics library. It does exactly that:

print en.verb.present("gave")
>>> give

Answer 2

With the help of NLTK this can also be done. It can give the base form of the verb. But not the exact tense, but it still can be useful. Try the following code.

from nltk.stem.wordnet import WordNetLemmatizer
words = ['gave','went','going','dating']
for word in words:
    print word+"-->"+WordNetLemmatizer().lemmatize(word,'v')

The output is:

gave-->give
went-->go
going-->go
dating-->date

Have a look at Stack Overflow question NLTK WordNet Lemmatizer: Shouldn't it lemmatize all inflections of a word?.

Answer 3

For Python3:

git clone https://github.com/clips/pattern
cd pattern
git fetch
git checkout development
pip install mysqlclient
python setup.py install

then

from pattern.en import conjugate, lemma, lexeme,PRESENT,SG
print (lemma('gave'))
print (lexeme('gave'))
print (conjugate(verb='give',tense=PRESENT,number=SG)) # he / she / it

yields

give ['give', 'gives', 'giving', 'gave', 'given'] gives

thnks to @Agargara for pointing & authors of Pattern for their beautiful work, go support them ;-)

Answer 4

JWI (the WordNet library by MIT) also has a stemmer (WordNetStemmer) which converts different morphological forms of a word like ("written", "writes", "wrote") to their base form. It seems it works only for nouns (like plurals) and verbs though.

Word Stemming in Java with WordNet and JWNL also shows how to do this kind of stemming using JWNL, another Java-based Wordnet library: