Don’t forget to remind them about the party. (Remember + to + infinitive and forget + to + infinitive refer to recalling (or not recalling) that there is something we need to do before we do it. Remember + -ing and forget + -ing refer to having (or not having) a memory of something in the past.)
I remember seeing you somewhere. (The same situation as with the previous one.)
Did you remember to water the plants today? (Already explained.)
We regret to tell you that you have failed this exam. (When 'regret' is followed by the gerund you feel sorry about something you did – or didn't do - in the past. When 'regret' is followed by the infinitive, you regret something you are about to say.)
He regrets making that mistake; now he doesn’t have money.(The same situation as with the previous one.)
After learning Spanish, she went on to make dinner. (Go on + to-infinitive means to do the next action, which is often the next stage in a process. Go on + gerund means to continue with an action.)
They went on discussing this question for hours.(The same situation as with the previous one.)
I’m sorry to interrupt, but can I ask you something? (When I want to express my regret about something I am doing now I need to use the form sorry + infinitive. When I want to express my regret about something I did in the past I need to use the form sorry + verb+ing.)
Bob was sorry for shouting at his little sister.(The same as with the previous one.)
He stopped smoking when he realized how dangerous it was.(Stop + -ing means the action is not happening any more. Stop + to + infinitive means that someone or something stops an activity so that they can do something else.)
