I have looked at pattern.en's conjugate, but it only conjugates into a few forms, and I would rather not have to sit down and program all of the exceptions to those rules that would allow me to make conjugations such as
nltk has stemming, but it doesn't seem to have the reverse operation, at least from searching StackOverflow. This seems like a very elementary NLP task, but I cannot find anything modern that does this in Python. Any general conjugation tool would be nice, although the progressive form in English doesn't have irregularities I know of.
I am also trying to see if there are exceptions to this rule, which might work as an alternate function:
def present_to_progressive(x):
vowels = set(['a','e','i','o','u'])
size = len(x)
if size == 2:
return x + 'ing'
elif x[size - 2:] == 'ie':
return x[:(size-2)] + 'ying'
elif x[size - 1] not in vowels and x[size - 2] not in vowels:
return x + 'ing'
elif x[size - 1] == 'e' and x[size-2] not in vowels:
return x[0:(size-1)] + 'ing'
elif x[size - 1] not in vowels and x[size-2] in vowels:
if x[size - 3] not in vowels:
return x + x[size-1] + 'ing'
else:
return x + 'ing'
else:
return x + 'ing'
Edit: Added case for "ie" verbs
There is an entire library for this type of modification that does what you want. It is called pattern.en
you can find it here: pattern.en
It is a good source.
Here is an excerpt from the conjugation tutorial on the site:
conjugate(verb,
tense = PRESENT, # INFINITIVE, PRESENT, PAST, FUTURE
person = 3, # 1, 2, 3 or None
number = SINGULAR, # SG, PL
mood = INDICATIVE, # INDICATIVE, IMPERATIVE, CONDITIONAL, SUBJUNCTIVE
aspect = IMPERFECTIVE, # IMPERFECTIVE, PERFECTIVE, PROGRESSIVE
negated = False, # True or False
parse = True)
It is quite useful and very expansive!