was/were

you were/you was...

I am confused with this form of usage.

With YOU it is always WERE (You were, I wish you were, If you were Superman...)
With I, it depends (I was, I wish I was/(were), If I were/(was) Superman...)

The "standard" form in most dialects is "were" - You were in Washington
In other dialects (apparently more than one), "was" can be used - You was in Kingston

You'll hear the singular used in AAVE, for example in hip-hop songs: "Is you ready?"

<<"Is you ready?" >>

Yes I ams!

I says that I ams!