When speaking of a group of people and referring to a body part of which there is only one (e.g. head, nose, mouth, etc.), do we use the singular or plural form? Which of the following is correct, or are both possible?
Our stomach is full.
Our stomachs are full.
In both cases:
Let's put our heads together and solve this problem quickly.
and
Now that our stomachs are full, we can think more clearly about the problem.
use the plural. Using the singular suggests a joint body part, which is not the case.
For your example, you should definitely use the plural, however there can sometimes be ambiguity in English. For example, how many legs get broken in this sentence?
John and James collided on the ski slope and broke their legs.
A better version would be
John and James collided on the ski slope and each broke his leg.
But what if it's John and Jane?
John and Jane collided on the ski slope and each broke their leg?
or
John and Jane collided on the ski slope and each broke a leg?
Neither works perfectly, in my opinion, so it can be an awkward way of saying things.
