When I check TOEFL essays, I often see grammar mistakes involving “stopped to VERB” and “stopped VERBing.” This is a dangerous mistake since these forms are used to express totally different ideas. The mistake often results in a sentence with the complete opposite of the writer’s intended meaning!
Here’s what you need to know.
“I stopped VERBing” means that I stopped doing that action.
“I stopped dancing in 1997” means that I stopped dancing in 1997.
“I stopped doing homework” means that I stopped doing my homework.
Easy, right? This is what most people want to express. This is probably what you should use in your essays.
“I stopped to VERB” means that I actually did the action!
“I was walking to school and I stopped to buy a sandwich” means that I bought a sandwich while you were walking to school.
“Yesterday, I stopped to talk to Simon” means that yesterday I talked to Simon.
The tricky thing is that after some English verbs you can use either an -ing form or an infinitive. But after other verbs you cannot.
What’s worse is that after some verbs this results in a different meaning, but after other verbs it does not.
For reference and verb lists, I recommend sections 100, 105 and 110 of “Practical English Usage.”