I have something in my eye.

我的眼睛里进了什么东西。

I've got a piece of grit in my eye.

我眼里进了一粒沙子。

I had a piece of grit in my eye.

我眼睛里进了一粒沙子。

When I cut the lemon, juice squirted in my eye.

我切柠檬时，柠檬汁溅到了我眼睛里。

If you were a teardrop, in my eye.

如果你是我眼里的，一滴泪。