A less vulgar way to say wth for people who like to avoid using or implying the wordhell in their language. It effectively removes the ambiguity of what the 'h' stands for.
A quick way to say "what the fuck" without the severity. You've been angered, but you're not angry enough to dish out "what the fuck" or even "what the actual fuck." Also possible as a work-safe variant of "what the fuck."
Jack: So you have to write eightpapers by noon tomorrow.
Jill: W the f.
"Wthefu" short for what the fuck, is a quick way people pronounce "What the fuck" when they'reconfused. It's also a way to pronounce "Wtf" if you actually pronounce wtf as weh-tef..