I went to parent-teacher conferences, and it was not what I expected.

Question

I have learned that at parent-teacher conferences not all the parents show up.

Are those sentences correct?

Answer 1

In the first sentence, you have "conferences" (plural) and then "it" (singular) to refer to "conferences." They don't match. You have a pronoun-antecedent mis-match here.

http://grammar.ccc.commnet.edu/grammar/pronouns.htm

The second sentence is fine.