Stop Smoking or Stop to Smoke? (gerunds and infinitives)

-ing or to ...

The –ing form (gerund) functions like a noun and describes a general activity.
The to .. form (infinitive) is a verb and indicates a particular action.

When you remember something you have a picture in your mind of something (an object, a person, an activity) you saw or heard in the past.

When you remember to do something you keep an idea in your mind of an action you have to do in the future.

When you stop something (an object, a person, an activity) you stop something that already exists in the present.

When you stop to do something you stop (a present activity) in order to do an action in the future.

I gave you a letter yesterday. Did you remember _____________ it?
1. to post
2. posting
Do you remember _____________ Marilyn Monroe in Gentlemen Prefer Blonds when we were students?
1. to see
2. seeing
I forgot _____________ any eggs so we can't make an omelette.
1. to buy
2. buying
You may have forgotten _____________ St Paul's Cathedral, but I remember it very well.
1. to see
2. seeing
He's so boring! He never stops _____________ about his new job.
1. to talk
2. talking
He stopped the car _____________ the hitch-hiker a lift.
1. to give
2. giving
She went on _____________ until she was exhausted.
1. to run
2. running
They finished the first question in the exam and went on _____________ the second one.
1. to do
2. doing
We regret _____________ you that your son has been reported missing in action since May 22, 1942
1. to inform
2. informing
I'll never regret _____________ this computer!
1. to buy
2. buying