Homunculus Servant's stat block reads:
Languages understands the languages you speak
It doesn't seem like it can actually talk back, though, because of the verb "understands" being used here - if a servant could talk, I might expect to read "speaks the languages you speak". But a DM could rule that "understanding a language" is sufficient to speak it.
As a counterexample, Giant Owl's Languages section specifically calls out that it cannot speak its understood languages (emphasis mine):
Languages Giant Owl, understands Common, Elvish, and Sylvan but can’t speak them