had never seen
I had never seen this kind of fish before.
それを「タイプする」と呼ぶのは知っていたけれど、彼がやるのを見たことはなかった。
I knew it was called “typing,” but I’d never seen him do it.
校長の気性が荒いという話は聞いていたが、実際に怒るところを見たことはなかった。
I’d heard the principal had a temper, but I’d never actually seen him get angry.
I had never seen a panda before then.