present
I back
You back
He backs
She backs
It backs
We back
They back
past
I backed
You backed
He backed
She backed
It backed
We backed
They backed
future
I will back
You will back
He will back
She will back
It will back
We will back
They will back
conditional
I would back
You would back
He would back
She would back
It would back
We would back
They would back