Pronouns

"It" would indeed be better, because "class", while collective, is also singular (one class) non-gender. If it were "classes", "they" would be more appropriate.

This seems to be an example of synesis, also called notional agreement. The word "class" is singular, but takes plural agreement because it is perceived as plural (being composed of many people). This is recognized by many grammarians as a normal part of English.

In the UK it is more common for nouns like "team, government, faculty" to take plural agreement, and in North America it is more common for them to take singular agreement. But there is nothing wrong with either usage.

Jessica, these are collectives, analyzable as either a unit (singular) or as a collection of individuals (plural). Selection of singular or plural verb or pronoun has less to do with the subject being marked with plural {-(e)s} or not than it has to do with the sense of what's expressed. Try this:

The team has/have finally arrived!

If you're American, there's a good chance that your natural grammar will prefer 'has', singular, i.e. team as a unit (probably with all arriving at once, e.g. all transported by one bus). Then try this:

The team showered, dressed, and then it/they went to a dinner in honor of its/their coach.

Most Americans would probably select they/their, i.e. each individual showered, dressed, and went to the dinner (unspecified/irrelevant as to whether together in a bus or separately).

In some cases usage is so fossilized that what formally looks like a singular (no {-(e)s}) is an unmarked plural: cattle, police, people (but the otherwise equivalent 'gente' as singular in Italian, Portuguese, Spanish).

In some cases usage varies by variety language-internally, as John notes: US 'Ford is experiencing a drop in sales', UK 'Ford are experiencing a drop in sales'.

The answer to your question is "Do what comes naturally to you."

'The Beatles were...'

'The Stones were...'

But if not marked as plural:

'The Who was/were perceived by many as number three, behind the Beatles and the Stones.'

Your choice!

While "the class" is certainly singular, consider the intent. A situation is implied where the teacher is trying in vain to get the students in the class to do something. If you use "it" instead of "they", then you ignore the fact that each student is free to listen to the teacher or not. You require the class to act in unison in their disobedience, which does not make any sense at all. You also ignore the possibility that every student could be ignoring the teacher's advice, but still not necessarily doing the same thing. "Do what you want" addressed to a group usually means that each individual can do something different (unless, they're all voting on a single group activity).

If one wanted to be pedantic, I guess one could make a case that the sentence is weak and should be recast. You could eliminate the mismatched case and potential amgibuity by , say, changing "told the class..." to "told the students in the class..."

I think the sentence is grammatical fine but informal and more likely to be spoken than written because of its pronoun reference.

Make that "grammatically fine."

Porsche is exactly right on this one. It depends on the context. Also, be aware of your audience; you certainly do not want to imply that a collection of humans are sub-human by referring to them as "it." Maybe, it's just my in-the-classroom bias, but I'd be careful about that one.

I again agree with prosche that the sentence would be better if recast.

Why fix a problem when you can eliminate it?

Thank you all very much for your help! I really appreciate it and I'll tell the class when the teacher returns.

I get a lot of students who use "they" as a pronoun for singular nouns in order to avoid the whole gender thing. That isn't the issue here, I know, but it is another example of the frequent confusion about noun-pronoun agreement that I see in too many papers.

I do appreciate the explanation above for collectives that are plural in Britain and singular in the US. I sometimes stumble on that.

http://language4you.wordpress.com

Two choices:

All plural: The teacher told [the members of] the class to do whatever they want.

All singluar: The teacher told the class [as a whole] to do whatever it wants. (i.e. whatever the class as a group decides).

Without more context, one can't really say which is more correct.

I heard it speculated, perhaps in the Ken Burns documentary, The Civil War, that the divergence between the British use of "are" and the American use of "is" when referring to collective nouns was triggered by that war. The United States went from being a collective entity of individual states to being a single nation, at least in the minds of Northerners.