the subjuect of a sentence may be what parts of speech?

Answer 1

The subject of a sentence may be a noun or a pronoun.

Check these sites for information about sentence structure and parts of speech.

http://www.towson.edu/ows/sentencestruct.htm

http://www.arts.uottawa.ca/writcent/hypergrammar/sntstrct.html

http://www.arts.uottawa.ca/writcent/hypergrammar/partsp.html

Answer 2

Ms. Sue is correct and she's given you some excellent websites.

Remember that almost all subjects are either nouns or pronouns, but once in a great while a gerund phrase or an infinitive phrase or a relative clause can serve as a subject. Those are rare, but they do happen.

http://grammar.ccc.commnet.edu/grammar/phrases.htm#gerund
Notice the 1st example.

http://grammar.ccc.commnet.edu/grammar/phrases.htm#infinitive
Notice the 3rd and 4th examples.

http://grammar.ccc.commnet.edu/grammar/clauses.htm#noun
Scroll down until you see the section on NOUN CLAUSES -- there are examples there.