THE INFINITIVE

1. Form
The infinitive is the base form of a verb. It may be preceded by 'to' (the to-infinitive) or stand alone (the base or zero infinitive).

2. Infinitive with or without 'to'

The to-infinitive is used:

a. after certain verbs. e.g. want, wish, agree, fail, mean, decide, learn
b. after the auxiliaries to be to, to have to, and ought to
c. in the pattern 'it is + adjective + to-infinitive'

Examples:

with 'to'

	The elephant decided to marry the mouse
	The mouse agreed to marry the elephant
	You will have to ask her
	You are to leave immediately
	He ought to relax
	She has to go to Berlin next week
	It's easy to speak English
	It is hard to change jobs after twenty years
	It's stupid to believe everything you hear

without 'to'

	I would rather visit Rome.
	She would rather live in Italy.
	Would you rather eat steak or fish?
	He would rather work in a bank.
	I'd rather be a forest than a tree.

FUNCTION

The most common uses of the infinitive are:

To indicate the purpose or intention of an action (where the 'to' has the same meaning as 'in order to' or 'so as to'):

	She's gone to collect her pay check.
	The three bears went into the forest to find firewood.

As the subject of the sentence:

	To be or not to be, that is the question.
	To know her is to love her. (Note: this is more common in written English than spoken)

With nouns or pronouns, to indicate what something can be used for, or what is to be done with it:

	Would you like something to drink?
	I haven't anything to wear.
	The children need a garden to play in.

After adjectives in these patterns:

	It is + adjective +to-infinitive It is good to talk
	It is + adjective + infinitive + for someone + to-infinitive. It is hard for elephants to see mice
	*It is + adjective + infinitive + of someone + to-infinitive.* It is unkind of her to say that.

After an adjective + noun when a comment or judgment is being made:

	It was a stupid place to park the car.
	This is the right thing to do.
	It was an astonishing way to behave.

With too and enough in these patterns:

too much/many (+ noun) + to-infinitive
There's too much sugar to put in this bowl.
I had too many books to carry.

too + adjective + to-infinitive
This soup is too hot to eat.
She was too tired to work.

too + adverb + to-infinitive
He arrived too late to see the actors.

enough (+ noun) + to-infinitive
I've had enough (food) to eat.

adjective + enough + to-infinitive
She's old enough to make up her own mind.

not enough (+noun) + to-infinitive
There isn't enough snow to ski on.

not + adjective + enough + to-infinitive
You're not old enough to have grand-children!

INFINITIVE AFTER QUESTION WORDS

These verbs: ask, decide, explain, forget, know, show, tell, understand, can be followed by a question word such as where, how, what, who, when or 'whether' + the 'to-infinitive'.

Examples:

	She asked me *how* to use the washing machine.
	Do you understand *what* to do?
	Tell me *when* to press the button.
	I've forgotten *where* to put this little screw.
	I can't decide *whether* to wear the red dress or the black one.

The question word Why is followed by the zero infinitive in suggestions:

Examples:

	Why wait until tomorrow?
	Why not ask him now?
	Why walk when we can go in the car?
	Why not buy a new bed for your bedroom?
	Why leave before the end of the game?
	Why not spend a week in Beirut and a week in Baghdad?

NEGATIVE INFINITIVE

To form the negative infinitive, place not before the to- or zero infinitive:
e.g. not to worry:

It's hard not to worry about exams.

Examples:

	I decided not to go to London.
	He asked me not to be late.
	Elephants ought not to marry mice.
	You'd better not smile at the crocodile.
	I'd rather not eat meat.

VERBS NORMALLY FOLLOWED BY THE INFINITIVE

A. The to-infinitive is used after the verbs in this group, without a preceding noun. The verbs marked * can also be followed by a 'that-clause'

Example:

VERB

TO-INFINITIVE

I hope...

to see you next week.

THAT- CLAUSE

I hope...
that I'll see you next week

afford
agree*
aim
appear ?
arrange*
bother
care
claim*
condescend
consent
decide*
demand*
determine*
endeavour

fail
guarantee*
happen ?
hasten
have (= be obliged)
hesitate
hope*
learn
long
manage
offer
prepare
pretend*
proceed

promise*
propose
prove (= turn out)
refuse resolve*
seek
seem ?
strive
swear*
tend
threaten*
trouble
undertake
volunteer
vow*

? These verbs can only be followed by a 'that-clause' when they have the subject 'it'. e.g. It appeared that no-one had locked the door.

Examples:

	He claimed to be an expert.
	I managed to reach the top of the hill.
	I know you're only pretending to love me!
	Don't pretend that you know the answer.
	She failed to explain the problem clearly.
	The customs man demanded to search our luggage.
	I can't afford to go out tonight.

B. These are the most common of the verbs that are normally followed by a noun + infinitive. The verbs marked * may also be followed by a 'that-clause'.

Example:

VERB

NOUN

INFINITIVE

He reminded

me

to buy some eggs.

THAT-CLAUSE

He reminded me
that I had to buy some eggs.

accustom
aid
appoint
assist
cause
challenge
command*
defy
direct*
drive
empower
enable
encourage
entice
entitle
entreat
force
get
implore*
incite
induce
inspire
instruct*
invite
lead
leave (make someone responsible)
oblige
order*
persuade*
press
prompt
provoke
remind*
require*
stimulate
summon
teach
tell
tempt
trust*
warn*

Notes:

command, direct, entreat, implore, order, require, trust:
there is no noun between these verbs and a 'that-clause':

	The general commanded his men to surrender.
	The general commanded that his men should surrender.

persuade and remind:
there is always a noun between these verbs and a 'that-clause':

	You can't persuade people to buy small cars.
	You can't persuade people that small cars are better.

instruct, teach, warn:
the noun is optional between these verbs and a 'that-clause':

	She taught her students to appreciate poetry.
	She taught her students that poetry was valuable.
	She taught that poetry was valuable.

Examples:

	The professor challenged his students to argue with his theory.
	This law empowers the government to charge more taxes.
	You can't force me to do something I don't agree with.
	You are obliged to drive on the left in England.
	I invited the new student to have dinner with me.
	What inspired you to write this poem?
	The elephant told the mouse to climb up his tail.

C. These are the most common of the verbs followed by a to-infinitive, with or without a noun.

Example:

	I asked him to show me the book.
	I asked to see the book.

ask*
beg*
choose
dare
desire*
elect

expect*
help
mean* (=intend)
request*
want
wish*

The verbs marked * can also be followed by a that-clause

Note:

dare: In negative and interrogative sentences the infinitive with or without 'to' is possible, though it is more common to omit the 'to':

	I never dared tell him what happened.
	Dare you tell him the news?
	Would you dare (to) jump out of a plane?

Examples:

	We've chosen John to represent the company at the conference.
	The elephant didn't mean to tread on the mouse.
	We expect you to do your best in the exam.
	Do you want to go to the beach?
	Do you want me to go with you to the beach?
	You are requested to be quiet in this library.