Most verbs take either a gerund or an infinitive, and the choice is mechanical. With a small group of verbs, both forms are grammatical — but they mean different things. Picking the wrong one does not sound awkward; it says something the speaker did not intend.
The eight verbs below work this way. For each one, the -ing form and the to-infinitive carry distinct meanings, and the contrast is worth learning as a pair.
Remember
Remember + -ing refers to a memory of something you did. The event happened; you can picture it.
Remember + to-infinitive refers to a task you need to do before you do it.
The -ing form looks backward at something real; the infinitive looks forward at something pending.
Forget
Forget + -ing is the mirror image of remember + -ing: failing to hold on to a memory. It is almost always used in the negative — I'll never forget… — because people rarely announce a memory they actually lost.
Forget + to-infinitive means failing to do something you intended to do.
Stop
Stop + -ing means to cease the activity named by the verb. The -ing form is the thing that stops.
Stop + to-infinitive means to interrupt one activity in order to do another. The infinitive is the reason for the pause.
This is the pair most often confused. Stopped smoking and stopped to smoke describe opposite behaviours.
Try
Try + -ing means to attempt something as an experiment — the action itself is easy, and the question is whether it will solve a problem.
Try + to-infinitive means to make an effort at something difficult, with the possibility of failing.
A useful test: if the verb is easy to perform and the goal is to see what happens, use -ing. If the verb is hard to perform at all, use the infinitive.
Regret
Regret + -ing expresses genuine regret for a past action.
Regret + to-infinitive is a formal lead-in to bad news, almost always followed by say, tell, inform, or announce. The speaker does not regret the act of informing; they regret the content of the message.
This pair is not really a contrast of meaning — it is a contrast of register. The -ing form is personal; the infinitive form belongs to formal letters and corporate announcements.
Go on
Go on + -ing means to continue the same activity without a break.
Go on + to-infinitive means to finish one activity and move to a new one.
The -ing form keeps you on the same track; the infinitive moves you to the next one.
Mean
Mean + -ing describes a result or necessary consequence. The subject is usually a situation, not a person.
Mean + to-infinitive describes intention. The subject is usually a person.
If the sentence can be rephrased as this will require…, the -ing form is correct. If it can be rephrased as I intended to…, use the infinitive.
Need
Need + -ing carries a passive meaning: something needs to be done to the subject.
Need + to-infinitive is active: the subject itself must do the action.
The -ing form works only when the subject is the thing being acted on. You can say the windows need cleaning but not I need cleaning in the same sense — that would describe the speaker, not a task.
Common mistakes
Remember and forget
Stop and try
Regret, go on, mean
Need