But this is, indeed, one of the fuzziest of all fuzzy areas in grammatical study. So I won't make a big deal of it here. In examining parts of speech, I will examine both form and function, separately as much as possible. Keep in mind that these are not called major because they are the most common parts of speech. Mainly, the term refers to their use as heads of phrases that make up the constituents in basic sentence patterns.
Nouns are words that name.
Another more technical word for this naming function is nominal . Nouns function as head words in NPs serving as subjects, direct objects, indirect objects, subject complements, object complements, and objects of prepositions. This is a good example of the difference between part of speech and phrase. Try these out. In our chapter on the auxiliary verb, we have thoroughly examined auxiliaries.