"My character doesn't speak common"
(this lead to a game breaking up for me)
This is actually one of my characters. Since everyone can speak Elvish (or Undercommon, not sure which) it isn't a big deal outside of the human places, anyway. Which she hates being in.
"I seduce the important guy"
Right after failing at intimidating him. The same game also had regularly repeated "your arm's broken" since another player kept trying to do things with two hands.
This came up with us briefly in our Witch U games. In that setting Common is technically Witchtongue, a magical language all witches know. Due to reasons, we weren't able to use our witch powers and subsequently also lost Common. Turns out, the party was split with a bunch of different languages, with half of us speaking Infernal and the other half French (because this is Earth).
Oh, and yes...
"You can't, it's a cutscene."