I am looking for a way given an English text count verb phrases in it in past, present and future tenses. For now I am using NLTK, do a POS (Part-Of-Speech) tagging, and then co
You can do this with either the Berkeley Parser or Stanford Parser. But I don't know if there's a Python interface available for either.
Thee exact answer depends on which chunker you intend to use, but list comprehensions will take you a long way. This gets you the number of verb phrases using a non-existent chunker.
len([phrase for phrase in nltk.Chunker(sentence) if phrase[1] == 'VP'])
You can take a more fine-grained approach to detect numbers of tenses.