Suggestion and order to repeat unknown (to target) language?

[deuxhero]

Can Suggestion force a target to correctly repeat a phrase from language they don't know and couldn't repeat by pure mimicry? Assuming the target would be physically capable of speaking it if they knew it.

[Kimera757]

I think it could (as in, I could order an NPC to repeat some nonsense syllables, which is effectively what is happening)...

Except a character without photographic memory needs to make some sort of Int or Wis check to get it right. People can have trouble with tongue-twisters in their own language, much less what is effectively a string of nonsense syllables.

[toastedamphibian]

I cannot make them do anything they could not otherwise do. You could compel them to cook a gourmet meal, or make a masterwork bastard sword in two days... they would try, if you can make such activity "sound reasonable", but success or failure will depend upon their actual skill.

I would go with a Linguistics check, DC determined by how familiar they are with the language in question.

[Claxon]

This isn't something that I expect to be covered by the rules, as a GM my ruling would be absolutely not.

Suggestion gets you to take a course of action, to the best of you ability.

They would do their best to repeat whatever words you said, but would probably mangle it enough for it not to work for whatever purpose you're thinking of.