I'm bilingual (English and Polish), though not because I need to, it just happened, sorta... I'm studying two philologies at my uni at the mo. That's English and Japanese. I also speak a little German and Spanish. But just a little

Bu-un, ki-en, etc. And other double t words end up being a d sound. (chader instead of chatter)
My American phonetics teachers call this a 'tap' or 'flap'