What happened - it’s the Past Simple Tense What’s happened - what has happened - it’s the Present Perfect Tense. If an action was only completed very recently, you can describe it with the present perfect tense.

Hi what is your English level?

Grammer: 'What's happened' is grammatically correct meaning 'What has happened' Difference: 'What happened' - past tense 'What's happened' - near tense 'What has just happened'

This is a really good question. While people will give the normal comparison between past tense and present perfect, it’s not that simple. I meet my friend and he has a broken arm. It happened in the past and it is still relevant now. So some will say it should be ‘What has happened?’ However, it is much more natural to ask ‘What happened (to you)? I think this is because ‘happened’ relates to a very specific point in the past. I happened to see him. Means I saw him without out arranging it. I have happened to see him. Not correct at all.