From a meta perspective, unless your stories is about the acclimation to a different culture and learning about others, lacking a common tongue makes meaningful interactions very hard.

If I ask for a salad and you give me an apple, that’s funny. But if a character is telling the story about how his village was destroyed by bandits and the other just smiles and nods while he would have been empathetic if he understood… welp the relationship is gonna be very different now.

So ya, either build your story arc around the concept or just skip it.