The German phrase for “shut up” is “Halt die Klappe.” It is a direct and informal way to tell someone to be quiet. It is considered impolite to use this phrase in formal settings or with people you do not know well.
There are other, more polite ways to ask someone to be quiet in German. For example, you could say “Bitte sei leise” (“Please be quiet”) or “Kannst du bitte leiser sein?” (“Can you please be quieter?”).
