Help with Plural Objects and Subjects

Question

I know to use 'is' for singular and 'are' for plurals.

I was recently listening to a song and it reminded me of a 'rule' a teacher once told me about.

The chorus repeats: Line 1: BIG GIRLS CRY WHEN THEIR HEARTS ARE BREAKING.

Normally, this is what i would write because it is talking about multiple gorls and it is not a collective noun (i dont think it is?). But then the song continues with....

Line 2: BIG GIRLS CRY WHEN THEIR HEART IS BREAKING.

This is what a teacher had once told me would also be correct and his justification was, although there is more than one girl, it would be incorrect to say 'hearts' as you are describing more than one girl who each has only one heart. So in other words, if we are talking about a group of people and describing for example a body part that there is only one of, it would be correct to word it the same way as Line 2.

Now my boyfriends mother who is also very good at grammar seems to disagree so i am right back to being confused again! Can anyone clarify please?? Thanks in advance.

Answer 1

What your teacher told you is close, but he or she was a bit confused. The problem is not so much that the reasoning is obviously wrong, it's that the example would then be ambiguous. Ambiguous? Yes. The sentence could also mean that big girls (collectively) have a single, common heart, and when it is breaking, they (collectively) cry. In addition to sentence 1, if you want to use the singular, "Any big girl cries when her heart is breaking." will also communicate the idea. With at least two different constructions to express the same idea, using an ambiguous version is not a good idea.

Despite this, the construction of sentence 2 can be used quite properly. "Americans are outraged when their flag is desecrated" is an example. In this case the construction works because both the individual and common versions of "flag" can be used. That is, if you're talking about an individual American and his or her personal flag, the sentence makes sense. Likewise, Americans collectively can be outraged if an American flag is misused. See, for instance, the Ted Landsmark incident http://en.wikipedia.org/wiki/The_Soiling_of_Old_Glory.