动词 “forget” 表示 “忘记”，其后可接动词不定式 “to do” 或动名词，分别组成搭配 “forget to do” 和 “forget doing”。“Forget to do” 和 “forget doing” 之间有区别么？如果 “你忘记锁门了”，应该使用哪一个搭配？

1. 我们用 “forget to do” 来表示 “本来应该做某事，但是因为忘记了，所以没有做”。

I forgot to lock the door.

He has forgotten to do his homework again!

Don't forget to wash your hands.

I forgot to feed the cat. She's really hungry.

2. 我们用 “forget doing” 来表示 “不记得做过某事”。

I forgot locking the door.

I had forgotten going to Paris until I saw the photos.