"Is" versus "are"

Question

I have a super silly question. I've been living abroad too long and teaching low level ESL has done the BYElingual thing to me.

This sentence "Reading comic books is bad." should the "is" be "are" or is that sentence correct? I know plural nouns (books) get plural are, but is the "is" in this case connected to reading? This sentence is from a textbook I'm teaching and it sounds a bit odd to me.

I have a similar confusion with "What is/are Jack and Sally's favourite subject?" I know these sentences are super basic, and I've searched online but couldn't get a specific answer. This is what I think: Jack and Sally become they, therefore "what ARE their favourite subject?" Correct?

Answer 1

Look for what the verb should agree with.

In your first example, the verb is related to "reading":

• Reading (something) is (whatever).

This isn't because reading is 'singular', but because reading has singular agreement.

In your second example, it's the favourite subject:

• What is (their) favourite subject?

If one person had multiple subjects (dropping 'favourite' to avoid any "just one" connotation), agreement is still with subject:

• What are John's subjects?