What are infinitives? |gerund and imperative form of verbs

Infinitives are the base form of a verb, often proceded by the word "to". They can function as nouns, adjectives or adverbs in a sentences.

Infinitives can express actions, intentions, or purposes. Infinitive often appear after verbs. For example:

The rain began to fall.
Sally and I agreed to meet this afternoon.
I've arranged to see the doctor at 3 o'clock.
I hope to visit Disneyland someday.
I like to ride my bike in the street.
My parents have decided to buy a new car.
Paul is learning to swim.
I didn't meant to upset you.

Some verbs have an object before the infinitive.

Simon asked me to help him.
The teacher told us not to run in the corridor.
Susie persuaded her friends to play on the team.
The manager allowed the stuff to leave early.

Infinitives often appear after adjectives.

The boys were afraid to cross the busy road.
I'm very pleased to see you again.
This problem will be difficult to solve.
The shelf is too high to reach.
Don't you think it's rude to ignore the new girl in class?.
The experiment was interesting to watch.
You're welcome to come with me.

You can also use infinitives after some nouns and pronouns to say what you are using something for.

Take a book to read.
I phoned for a taxi to take us to the airport.
Has everyone got something to drink?
I've got lots of nice calothes to wear.
Find a space on the floor to sit in.

Infinitives sometimes follow words like how, what, which and where.

My brother is learning how to Cook.
I can't decide which to choose the ice cream or the pudding.
I don't know to say.
Sally can't remember where to hang her coat.

Infinitives are also used after helping verbs such as will, can, should, may and must. After these helping verbs use infinitives without to.

I can swim.
We think she will win the race.
You must try harder.
Do you think we should wait?
May I come in?

Notes: the helping verbs will, can, should, may, and must are called auxiliary verbs.

The imperative form of verbs

When you give an order or command, use the base form of a verb, such as give, read or come. This base form is called the imperative.

Open your books to page 25.
Stop and look before you cross the road.
Come to the front of the class.
Show me your homework.
Read the first sentences out loud.
Choose a partener and stand in a circule.

Imperatives are very direct. To be more polite, you can use please before the imperative.

Please show me your homework.
Please read the first sentence out loud.
Please come to the front of the class.

To make negative imperatives, use do not or don't before the base form of the verb.

Do not bring calculators into the exame room.
Please don't change anything on my computer.

Gerund

A gerund is a verb form that ends in - ing and functions as a noun in a sentences.

A gerund is the ing form of a verb used as noun. Sometimes a gerund is called a verbal noun because it come from a verb.

Gerund can act as the subject of a sentence, the object of a verb, or the object of a prepositions.

Running is a good way to keep fit.
Susan is very good at drawing.
He loves dancing and singing.
Have you ever tried sailing?
I don't like watching television.
We enjoyed visiting our grandparents.

Notes: sometimes it is difficult to know whether an ing word is a gerund or a present participle. If you can replace the ing word or its phrase with pronoun it, then the word is a gerund.

Some gerunds can be used in front of other nouns, like adjectives.