GOOD EXPLANATION
tim wrote:
The primary S-V-O combination is acquaintances-are-those; i'm guessing that's not the one you had trouble with..
The secondary S-V-O combination is we-like-whom, and whom=acquaintances..
You can usually tell on these by identifying the verb first: LIKE. Now who is doing the liking? WE are. Now what do we like? ACQUAINTANCES. Of course, ACQUAINTANCES here has been replaced by a pronoun. That's exactly why we need WHOM rather than WHO, because it is an object..