Verbs that change meaning

These verbs take either -ing or to-infinitive, but the meaning changes completely.

Verb+ -ing+ to infinitive
stop Stop doing = quit, no longer do it
"She stopped smoking." (= she quit)
Stop to do = pause in order to do something
"She stopped to smoke." (= she paused and had a cigarette)
remember Remember doing = recall a past action
"I remember meeting her at the party." (= I recall it)
Remember to do = not forget to do something
"Remember to lock the door!" (= don't forget)
forget Forget doing = no memory of doing it
"I'll never forget meeting you." (= I'll always remember)
Forget to do = fail to do something
"He forgot to buy milk." (= he didn't do it)
try Try doing = experiment, see what happens
"Try turning it off and on again." (= experiment)
Try to do = attempt (may be difficult)
"I tried to open the jar." (= attempted, probably failed)
go on Go on doing = continue the same activity
"She went on talking for hours." (= kept talking)
Go on to do = move to a new, different activity
"He finished school and went on to study medicine."
regret Regret doing = feel sorry about a past action
"I regret saying that to him." (= I said it — sorry now)
Regret to do = sorry to do something now (formal announcement)
"We regret to inform you that…"

Gerund after prepositions

After any preposition, the verb must be in the -ing form (never to-infinitive).

PatternExample
interested in + -ingShe's interested in learning Japanese.
good at + -ingHe's good at playing chess.
instead of + -ingInstead of waiting, she left.
without + -ingHe left without saying goodbye.
after / before + -ingAfter finishing her work, she went out.
used to + -ing (= accustomed)I'm not used to getting up so early.

Infinitive after adjectives

Many adjectives are followed by to + infinitive, especially to express feelings or judgements about an action.

PatternExample
happy / glad / pleased toI'm happy to help you.
surprised / shocked / delighted toShe was surprised to see him there.
easy / difficult / hard / impossible toIt's hard to understand his accent.
likely / unlikely toHe's unlikely to agree.
ready / prepared toAre you ready to start?

Exercises

Choose the correct form — -ing or to-infinitive.

1. He stopped ___ when he heard his name called. (= he paused)

2. I'll never forget ___ my first concert. (= I'll always have that memory)

3. Remember ___ the door when you leave. (= don't forget)

4. Try ___ lemon juice — it might help with your sore throat. (= experiment)

5. After university, she went on ___ a PhD. (= then moved to a new activity)

6. He left the party without ___ goodbye to anyone.