[Grammar] He was a good teacher. He is a good teacher.

[j1973555]

If I am talking with my friend about my teacher two years ago.

He was a good teacher.
He is a good teacher.

If I say "was" it means in the past which makes sense, but it means the teacher is only good in the past.

If I say "is" it means that he is good both in the past and present, but for the grammar part it doesn't makes sense since he no longer teaches me and I am talking about him in past tense.

 

[Tarheel]

He might not be your teacher anymore, but if he is still teaching you should use the present tense: "He is a good teacher."

 

[teechar]

If I am talking with my friend about my teacher from two years ago.

He was a good teacher.
He is a good teacher.

If I say "was", it means in the past, which makes sense, but it means the teacher [STRIKE]is[/STRIKE] was only good in the past.

If I say "is", it means that he is good both in the past and present, but for the grammar part, it doesn't makes sense since he no longer teaches me and I am talking about him in a/the past tense.

Ordinarily, you would use "was". That does not necessarily mean he is no longer a good teacher.
However, if the context is relevant to the present, e.g. you're both still at that school (but not being taught by that teacher), or that teacher still teaches in the school and your friend is one of his students, then the present simple would be appropriate.

 

[j1973555]

Thank you so much!! I've asked one of my native friends long time ago, but I couldn't remember what he said, so I mix it up often.

 

[j1973555]

thank you!

 

[teechar]

Thank you so much! [STRIKE]I've[/STRIKE] I asked one of my native friends a long time ago, but I couldn't remember what he said, so I often mix [STRIKE]it[/STRIKE] them up. [STRIKE]often.[/STRIKE]

Okay, now you know. ;-)

Thank you!

You're welcome. However, there's no need to write a post to say thank you. In future, just click Thank/Like to acknowledge a reply.