沒(méi)有what's happen,但有what's happened或what's happening
what happened曾發(fā)生過(guò)什么?
what's happened已經(jīng)發(fā)生了什么?
what's happening正在發(fā)生什么?能不能講講happen的其他用法please,thank you.（最好再加點(diǎn)例句）1.發(fā)生 It happened under my eyes.這事就發(fā)生在我眼皮底下。2.產(chǎn)生結(jié)果, 發(fā)生作用 He pressed hard on the brake but nothing happened.他使勁往下踩剎車, 但沒(méi)有發(fā)生作用。3.碰巧, 恰巧 What would happen if your parents found out?如果你的父母發(fā)現(xiàn)了, 會(huì)怎樣呢?It happens that he is a teacher of English.恰好他是個(gè)英語(yǔ)教師。