I'm reading a lot of books by self published authors, and sometimes there's half a page without a comma in sight. If they don't know their grammar, I would suggest they read the sentence, and put a comma, where they would breathe in...
Apostrophes have me extremely confused, as they're not really used in my native language. 'My daughter's husband', I believe, have and apostrophe in English, but not when translated to Danish. I guess, I'll never work it out...