"Spoke" or "speak" could both work. If he no longer speaks it well, if he's dead or if you're talking about a specific time when he spoke in the past, the Simple Past tense would be appropriate. If it's something that's generally true, the Simple Present is the better choice.

speaks, spoke, is speaking, will speak, had spoken, has spoken, will have spoken. All are correct. Without context it is not possible to choose one.