Despite the fact that I learned about it when I was in middle school,...

English grammar, which often rubs me the wrong way!

Yesterday, I taught a little bit about verbs. While preparing for class, I came across a problem regarding the present continuous (a.k.a. present progressive). Look at the sentence below:

Everybody was cheering.

What is a verb in this sentence? When I saw this sentence, I thought that there are three answers.

A) was

B) cheering

C) was cheering

This time I taught my students C) is the correct answer after taking with a couple of Americans. But, A) and B) are also possible answers. If you exclude helping verbs (a.k.a. auxiliary verbs), B) is okay. Also, if you think the past participle "cheering" is an adjective, A) is right.