The same as I/me/mine

Is he wearing the same shirt as me? OK.
Is he wearing the same shirt as I am? OK. My favorite of the four.
Is he wearing the same shirt as mine? OK, but just barely.
Is he wearing a shirt the same as mine? Not ungrammatical, but awkward to my ear.

You'll need a "his" to make "mine" sound right as the contrast:

Is his shirt the same as mine?

CJ

Thank you very much!

What if use the adjective 'different'?

i.e.
He's wearing a different shirt from/than me.
He's wearing a different shirt from/than I am.
He's wearing a different shirt from/than mine.
He's wearing a shirt different from/than mine.

Thank you

Hi lagataw

CJ will give his excellent advice on the variations, but if you wrote:

He's wearing a different shirt from me.

I could possibly interpret it that I had given him the different (unusual) shirt that he is wearing. (The shirt is from me.)

"From" is not what you want....

Cheers,
A-

CJ before you expound on this, I want to state it clear that my main inquiry is in the pronoun after than/from. But if you wish to explain the difference between 'from' and 'than', you may do so.
Thanks!

Oops, kinda sounded rude without the greeting.

Hi CJ should come first in my reply before this.

Is he wearing the same shirt as me? OK.
Is he wearing the same shirt as I am? OK. My favorite of the four.
Is he wearing the same shirt as mine? OK, but just barely.
Is he wearing a shirt the same as mine? Not ungrammatical, but awkward to my ear.

He's wearing a different shirt from/than me. OK.

He's wearing a different shirt from/t

lagataw Which one(s) is/are correct?
Is he wearing the same shirt as me?
Is he wearing the same shirt as I am?
Is he wearing the same shirt as mine?
Or you would go for
Is he wearing a shirt the same as mine?
Or another version?
Thanks