"What happened to you?" is common and accepted.
"What has happened to you?" is cool, too.
The first one is an informal wh-question. Something happened to you. What happened to you? Someone said it. Who said it?
The only difference is the axiliary 'has' in the second one. It adds emphasis.
Josh: Something happened to my face?
Nomi: What happened?
Josh: Well...erm...
Nomi: What HAS happened? Do tell!
Josh: I accidently walked into a tree. :?
Yeah, that's right, we learn together and I'm glad that I get the answer. By the way, could anyone tell me that why we use "it's an act of bravery" instead of "it's an action of bravery"? I still feel confused about this two sentences. Thanks a lot!! :bday:
An 'act' is like a unit of activity, while 'action' is the process. We say 'act of bravery' because we are referring to something that began and ended in clear terms, rather than talking in general terms.;-)