to + infinitive

 

We 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 sometimes say in order to or in order not to:

We set off early in order to avoid the traffic.
They spoke quietly in order not to wake the children

… or we can say so as to or so as not to:

We set off early so as to avoid the traffic.
They spoke quietly so as not to wake the children.

• after certain verbs (see verbs followed by infinitive), particularly verbs of thinking and feeling:

choose, decide, expect, forget, hate, hope, intend, learn, like,
love, mean, plan, prefer, remember, want, would like, would love

… and verbs of saying:

agree, promise, refuse

They decided to start a business together.
Remember to turn the lights out.

Some verbs are followed by a direct object and the infinitive(see verbs followed by infinitive):

advise, ask, encourage, invite, order, persuade, remind, tell, warn,
expect, intend, would prefer, want, would like

She reminded me to turn the lights out.
He encouraged his friends to vote for him.

• after certain adjectives.

Sometimes the to-infinitive gives a reason for the adjective:

  • disappointed
  • glad
  • sad
  • happy
  • anxious
  • pleased
  • surprised
  • proud
  • unhappy

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

Other adjectives with the to-infinitive are:

  • able
  • unable
  • due
  • eager
  • keen
  • likely
  • unlikely
  • ready
  • prepared
  • unwilling
  • willing

Unfortunately I was unable to work for over a week.
I am really tired. I’m ready to go to bed.

We often use the to-infinitive with these adjectives after it to give opinions:

  • difficult
  • easy
  • possible
  • impossible
  • hard
  • right
  • wrong
  • kind
  • nice
  • clever
  • silly
  • foolish

It’s easy to play the piano, but it’s very difficult to play well.
He spoke so quickly it was impossible to understand him.

We use the preposition for to show who these adjectives refer to:

  • difficult
  • easy
  • possible
  • impossible
  • hard

It was difficult for us to hear what she was saying.
It is easy for you to criticise other people.

We use the preposition of with other adjectives:

It’s kind of you to help.
It would be silly of him to spend all his money.

• As a postmodifier (see noun phrases) after abstract nouns like:

  • ability
  • desire
  • need
  • wish
  • attempt
  • failure
  • opportunity
  • chance
  • intention

I have no desire to be rich.
They gave him an opportunity to escape.
She was annoyed by her failure to answer the question correctly.

• We often use a to-infinitive as a postmodifier after an indefinite pronoun (See 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.


 

Exercise

Comments

Hello! I am wondering whether this sentence means the person has to do something: "the food to be eaten shall be three meals per day." In other words, is this a command? Or how would you describe it grammatically? Thanks!

Hello ballinke,

This form 'the [noun] to be [past participle]' is a formal form generally used in instructions, regulations and laws, so it may well be a command, depending on the context. It is a passive infinitive formed with [to be + past participle].

Best wishes,

 

Peter

The LearnEnglish Team

Hi

In the first page of your "English Grammar" you say
"Each section has interactive exercises to help you check understanding"
Could you please explain to me why there is "check" rather than "to check" or "checking"
and what is the general rule for that..(if there is one).

Many thanks

Hi Ilared,

When a verb is followed by another verb, the form of the second verb depends on what the first verb is. In the sentence you ask about, the first verb is help, which is a bit of an unusual case because it can be followed by a to + infinitive or a bare infinitive (i.e. infinitive without to). Both of the following sentences are correct:

Thanks for helping me to paint my flat.
Thanks for helping me paint my flat.

Normally you can't choose what form to use after a verb: generally, the second verb must be either in the to + infinitive form (explained above) or the -ing form.

Best wishes,
Kirk
The LearnEnglish Team

Hi Kirk,

thanks for your reply,
so what are you saying is that in general a verb could be followed by the to+infinitive or by the ing-form (and it depends from the verb) but there are some verbs that could be followed by a bare infinitive. Can I ask you if there are other verbs like "help" that allow a bare infinitive after them.

Thank you in advance,

Ilared

Hi 

The bare infinitive is used after modal verbs such as 'should', 'can', 'will' and so on.  It is also used after certain verbs in the structure [verb + object + bare infinitive]. These verbs include let, make, see, hear and feel.

Best wishes,

 

Peter

The LearnEnglish Team

Thank you teacher for this lesson, I have an interesting question, what about rest of adjectives that is followed by to + infinitive... you haven't mentioned them, only you've mentioned group of them.. I hope you'll comment for my question as soon as possible..

Hi Nawaf student,

You're right when you say that there are other adjectives that are like those explained above, but the purpose of our grammar pages is to help people learn the English they need for ordinary situations, not to provide an exhaustive list of every possible form. The list would be very long, indeed!

Best wishes,
Kirk
The LearnEnglish Team

Dear Sir,
                My name is Sumeet. I have seen the following three patterns in which the verb 'prefer' can be used.
1) Prefer + Noun + to + Noun
2) Prefer + Gerund + to + Gerund 
3) Prefer + Full infinitive + rather than +  Full / Bare infinitive 
I am confused about the 3rd pattern. Do we use full infinitive or bare infinitive after rather than in this pattern ? Some books say that we use full infinitive and some say that bare infinitive is used after rather than. Can you please exemplify it? Thank you so much in advance.

Hi Sumeet,

The third pattern you mention, with a full infinitive after rather than, e.g. "I would prefer to stay at home rather than to go to the party", doesn't sound right to me, but perhaps there are varieties of English in which that structure is correct.

What I have seen is prefer + full infinitive + rather than + bare infinitive / -ing form:
"I would prefer to stay at home rather than go (or going) to the party".

Best wishes,

Kirk
The LearnEnglish Team

 

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