It could happen/It can happen
Please explain about the differences of the following phrases.
Thank you.

It could happen to you.
It can happen to you.
It may happen to you.
It could happened to you.

It could have happened to you.

Question

It could happen/It can happen
Please explain about the differences of the following phrases. 
Thank you.

It could happen to you. 
It can happen to you. 
It may happen to you. 
It could happened to you.

It could have happened to you.

Answer

Hi, Sumit.
That was a valuable video and a big amount of my problems were solved.
Thank you.

Answer

https://www.youtube.com/watch?v=SaBH_huiJSM. Go through this link. Hope you understand through this video.

Answer

It could happen to you. (implied 75%)
It can happen to you. (implied 100%)
It may happen to you. (implied 50-50 chance)
It could happened to you. (wrong)

That's my intepretation.