Verbs with to-infinitives
We use the to-infinitive after certain verbs (verbs followed by to-infinitive), particularly verbs of thinking and feeling:
They decided to start a business together.
Remember to turn the lights off.
and verbs of saying:
We agreed to meet at the cinema.
Promise to call me every day.
Some verbs are followed by a direct object and then the to-infinitive:
He encouraged his friends to vote for him.
Remind me to give Julia a call.
- Verbs with to-infinitive 1
- Verbs with to-infinitive 2
Infinitive of purpose
We also use the to-infinitive to express purpose (to answer why?):
He bought some flowers to give to his wife.
He locked the door to keep everyone out.
We can also express purpose with in order to and in order not to:
We started our journey early in order to avoid the traffic.
They spoke quietly in order not to wake the children.
or so as to and so as not to:
We started our journey early so as to avoid the traffic.
They spoke quietly so as not to wake the children.
- Infinitive of purpose 1
- Infinitive of purpose 2
Adjectives with to-infinitives
We use the to-infinitive after certain adjectives:
Unfortunately, I was unable to work for over a week.
I'm really tired. I'm ready to go to bed.
Sometimes the to-infinitive gives a reason for the adjective:
We were happy to come to the end of our journey.
(= We were happy because we had come to the end of our journey.)
John was surprised to see me.
(= He was surprised because he saw me.)
We often use it + be followed by an adjective to give opinions:
It's easy to play the piano, but it's very difficult to play well.
He spoke so quickly that it was impossible to understand him.
We use the to-infinitive with these adjectives to give opinions about people:
She was right to complain about that hotel.
You were clever to find the answer so quickly.
We use the preposition for to show who these adjectives refer to:
It was difficult for us to hear what she was saying.
It is easy for you to criticise other people.
With the other adjectives, we use the preposition of:
It's kind of you to help.
It would be silly of him to spend all his money.
- Adjectives with to-infinitive 1
- Adjectives with to-infinitive 2
Nouns with to-infinitives
We use the to-infinitive as a postmodifier (see noun phrases) after abstract nouns like:
They gave him an opportunity to escape.
He was annoyed by her refusal to answer.
I have no desire to be rich.
There is no need to shout.
We often use the to-infinitive as a postmodifier after indefinite pronouns:
When I am travelling I always take something to read.
I was all alone. I had no one to talk to.
There is hardly anything to do in most of these small towns.
- Nouns with to-infinitive 1
- Nouns with to-infinitive 2
The sentence with the infinitive of purpose communicates the idea of staying up late with that purpose. The other sentence (with the -ing form) just describes what you did last night, without the idea of purpose -- maybe you were just bored, for example, or maybe you had to watch it before class today.
In some contexts, this distinction might not important, but the subtle difference is there.
All the best,
The LearnEnglish Team
Hello Andrew international,
You can find the answer to this in our grammar section with a little search. It's very helpful to us if you can first try to find the answer yourself before posting questions as it enables us to focus on those questions which do not already have an answer on our pages. This page is on an entirely different topic (to + infinitive); the relevant page for your topic, with the information you require, is here.
The LearnEnglish Team