Complete the sentences with the correct form of the verbs given in brackets (using gerund or infinitive).

Write one or two words in each gap.

I don't remember [ ] the front door. You should go back and check. (to lock)

Jack regretted not [ ] up for his rights when it was needed. (to stand)

Tim tried [ ] us, but it was no use. (to help)

I didn't mean to [ ] you. I'm sorry for what I've done. (to upset)