Idk, I’m bilingual and I only ever think in English. It doesn’t really seem to make a difference though, saying things out loud vs in my head.

I’m learning a third language now and can just barely communicate with others (worked with a taxi driver!). That said, I wouldn’t consider myself truly trilingual yet. I could think in that language but it doesn’t really feel like it changes anything - I still only know the same words in my head