Student or Learner
"Double possessive" is probably a misnomer, but since I don't know the correct grammatical term, "double possessive" will have to do. My question is whether the construction that follows is acceptable in formal writing:
"My mom's friend's son is paying us a visit."
The alternative is wordy - "A/The son of my mom's friend is paying us a visit" - but it has the advantage of informing the reader/listener of whether the friend has one or more sons.
I agree that it's clearer. I wouldn't call it clumsy though - so long as there are only two degrees of separation. Here's clumsy: 'My father's sister's brother's beard.'