有現在完成式問題想問問

I was discharged from the hospital last Sunday.
My friend went to the hospital to see me last Sunday.
He didn't see me as I had already left the hospital.

我宜家同我朋友講:

You didn't see me in the hospital last Sunday, because I had already been discharged earlier on.

~or~

I had already been discharged from the hospital before you came to see me last Sunday.

2015-04-07 23:56:00 補充：
如果你朋友在你出院之前來醫院探望你，他不知道你已經出院，宜家可以講:

I have already been discharged from the hospital. So, you don't have to come to see me in the hospital.

I have been discharged from the hospital."-The sentence is OK grammatically. It means that you have already been discharged from the hospital when you say so.

I was discharged from the hospital last Sunday - ok in past tense with time (last Sunday)