Tongue knot

you make a gesture to a target that knows a language you can see within 30ft. The target must succeed on a Charisma saving throw or lose the ability to speak it's last spoken language for the duration of the spell or until concentration is lost. The target can still speak any other languages than the taken language as long as the target can speak it. If the target only knows one language it will talk in incomprehensible gibberish instead, losing the ability to cast any verbal component spells.

when cast at level 1 or higher the caster can take 1 additional language from the target with each level.