I've never seen the sea before.

我以前从未见过大海。

I've never seen anything like it!

我从未见过这样的东西！

She had never seen anything like them.

她从未见过这样的东西。

I had never seen Prince Hamlet do a backflip before!

我从未见过哈姆雷特王子翻筋斗！

I had never seen anything so beautiful in nature before.

我以前从未见过如此美丽的大自然。

He's a good public speaker and I have never seen him get nervous.

他是个很好的演讲者，我从未见他紧张。

I have never seen him drunk.

我从来没有见过他酒醉的样子。

He has never seen a live eel.

他从未见过活的鳗鱼。

I have never seen him before.

我以前从未见过他。

He has never seen a real gun.

他从未见过真正的枪。