In the following code, why does nltk think \'fish\' is an adjective and not a noun?
>>> import nltk
>>> s = \"a woman needs a man like a fi
I am not sure what is the workaround but you can check the source here https://nltk.googlecode.com/svn/trunk/nltk/nltk/tag/
Meanwhile I tried your sentence with little different approach.
>>> s = "a woman needs a man. A fish needs a bicycle"
>>> nltk.pos_tag(s.split())
[('a', 'DT'), ('woman', 'NN'), ('needs', 'VBZ'), ('a', 'DT'), ('man.', NP'), ('A','NNP'), ('fish', 'NN'), ('needs', 'VBZ'), ('a', 'DT'), ('bicycle', 'NN')]
which resulted in fish as "NN".