1. My brother stopped (go) going to the youth club because he is very busy.
Explanation: "stopped + Ving" means to stop doing something that was already in progress.
2. She was late because she stopped (help) to help some children cross the street.
Explanation: "stopped + to V" means to stop what you are doing in order to do something else.
3. Where are the keys? I remember (lay) laying them on this table this morning.
Explanation: "remember + Ving" means to remember having done something in the past.
4. Remember (visit) to visit me when you come here.
Explanation: "remember + to V" means to remember to do something in the future.
5. I am sorry I have forgotten (do) to do what you said to me this morning. You have helped me a lot.
Explanation: "forget + to V" means to forget to do something that you planned to do.
6. I will never forget (work) working with you. You have helped me a lot.
Explanation: "forget + Ving" means to forget that you have done something in the past.
7. I regret (go) going out last night.
Explanation: "regret + Ving" means to regret having done something in the past.
8. I regret (inform) informing you that your application hasn't been accepted.
Explanation: "regret + Ving" means to regret doing something.
9. When I arrived, he was trying (start) to start his new car, there was something wrong with the machine. He even tried (work) working it downhill twice, but that didn't work either.
Explanation: "trying + to V" means attempting to do something. "tried + Ving" means attempted to do something in the past.
10. I didn't mean (eat) to eat anything but the cakes looked so good that I couldn't resist trying one.
Explanation: "mean + to V" means to intend to do something.