Oh no! Another quiz!

Here is another one of those 'stop-and-think-about-it' comparisons.

• It's both of our form of entertainment.
• It's both of our forms of emtertainment.

When do you use each of these? Is one correct and the other incorrect? Do they refer to singular and multiple forms of entertainment? Do they refer to entertainment for one group as opposed to multiple groups of people? Does both refer to us in the first one and to forms of entertainment in the second (meaning there are only two forms of entertainment in the second)?

Make a guess and I'll tell in the next post. ;-)