My preference is #4. It puts the "only" as close as possible to the period of time. That said, you'll hear all of these (#3, not so much, I think), and no one will be confused about the meaning.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
Grammar GeekMy preference is #4.
It puts the "only" as close as possible to the period of time.
No one will say "Oh, they've only KNOWN each other -- so else did they do together before they KNEW each other -- saw each other from across a hallway?" because they genuinely don't understand that only is modifying the period of time and not the nature of th