One of the first things my S/O learned about me that made her fall in love with me is what we call "Sleep Babbling" - when I'm clearly exhausted and trying to stay awake, my conversation responses will sometimes veer off into Makes-No-Fucking-Senseville.

A perfect example:

"So are you gonna be busy tomorrow?"

"I don't know, but I'm guessing so because there's the 24 hour Burger King mayhem."

lmao my bf does the same thing. Sometimes its English. Others its gibberish.
My favourites are when he wakes up but his brain is still kinda not all there.
He once aat up looked at our cat and said:

Who the fuck is that!?

me: who?

The cat.

That's Scurvy.....our cat.....

Oh.....................*flops in the bed*

It happen's when your working like a dog, guilty of this.
I just fell asleep though, never really babbled

I understand how it is hehe. I fall asleep while talking all the time.

X3