present
I happen
You happen
He happens
She happens
It happens
We happen
They happen
past
I happened
You happened
He happened
She happened
It happened
We happened
They happened
future
I will happen
You will happen
He will happen
She will happen
It will happen
We will happen
They will happen
conditional
I would happen
You would happen
He would happen
She would happen
It would happen
We would happen
They would happen