You didn't tell me that you have a girlfriend.(Does it mean that he still has a girlfriend)
orYou didn't tell me that you had a girlfriend.(Does it mean that he no longer has a girlfriend)
I knew that you have a girlfriend.
orI knew that you had a girlfriend.
which of them is grammatically correct and why not the other one? Please explain every detail about such sentences which give confusion of tenses to the non English speakers.
P.S The person does have a girlfriend at present, as he never broke up with her.
thanks in advance :)