Dell yeah

In the back woods country some might say dell yeah to define a stupid thing one is about to do or use instead of hell yeah

Hey bro I dare you to jump off the roof

Oh dell yeah

Is that you, yeah?

When you see an old friend and you feel the need to forget their name and ask if it is them, the more appropriate way of saying "Yo mate I see it is you"...

Ehhh fam! Is that you, yeah? Fam das you bruv.

Yeah, Markus

Something you say to someone when someone does something even remotely incorrect

Person 1: Places a lego brick SLIGHTLY incorrect
Person 2: Yeah, Markus