POS tagging - NLTK thinks noun is adjective

Question

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         


        

Answer 1

If you use the Stanford POS tagger (3.5.1) then the phrase is correctly tagged:

from nltk.tag.stanford import POSTagger
st = POSTagger("/.../stanford-postagger-full-2015-01-30/models/english-left3words-distsim.tagger",
               "/.../stanford-postagger-full-2015-01-30/stanford-postagger.jar")
st.tag("a woman needs a man like a fish needs a bicycle".split())

yields:

[('a', 'DT'),
 ('woman', 'NN'),
 ('needs', 'VBZ'),
 ('a', 'DT'),
 ('man', 'NN'),
 ('like', 'IN'),
 ('a', 'DT'),
 ('fish', 'NN'),
 ('needs', 'VBZ'),
 ('a', 'DT'),
 ('bicycle', 'NN')]