talk vs teach

talk is a noun but teach is not a noun.

Word	Noun	Adjective	Verb	Adverb
talk	Yes	No	Yes	No
teach	No	No	Yes	No

As verbs, teach is a hypernym of talk; that is, teach is a word with a broader meaning than talk:

Other hypernyms of talk include instruct, learn.

talk (noun)	teach (noun)
the act of giving a talk to an audience
an exchange of ideas via conversation
idle gossip or rumor
a speech that is open to the public
discussion; (`talk about' is a less formal alternative for `discussion of')

talk (verb)	teach (verb)
express in speech	accustom gradually to some action or attitude
exchange thoughts; talk with	impart skills or knowledge to
reveal information
use language
deliver a lecture or talk
divulge confidential information or secrets