How to Make Gerunds and Infinitives

What is a Gerund?

A gerund is a noun made from a verb. To make a gerund, you add "-ing" to the verb.

For example:
In the sentence "I swim every day", the word "swim" is a verb.

In the sentence "I like swimming", the word "swimming" is a noun.

Therefore, "swimming" is a gerund.

Second example:
In the sentence "She reads several books a week", the word "read" is a verb.
In the sentence "Reading is important", the word "reading" is a noun.
Therefore, "reading" is a gerund.

More examples of gerunds: buying, fishing, running, watching, telling, and so forth.

The word "gerund" actually comes from the Latin word gerere, which means "do".
You could say this actually makes sense: the gerund describes an action, something you do.
Gerunds are often used when actions are real or completed.

Examples:
(Note how the main underlined verb relates to real or completed actions.)

• She stopped smoking.
• I finished doing my homework.
• They keep on fighting.
• We discussed moving to Florida.
• You recommended waiting until tomorrow.
• He recalled falling asleep on the couch.
• She practices playing those drums all the time.
• John completed fixing the car.
• The job involves dealing with animals.
• Brian mentioned staying up late.
• They suggested not keeping the luggage.
• We started working on this yesterday.

What is an Infinitive?

An infinitive is the basic form of the verb + "to".

Examples: to buy, to fish, to run, to watch, to tell, and so forth.

Example Sentences:

"I want to swim."

"They asked us to leave."

"To be, or not to be – that is the question."

"The goal is to win."

The word "infinitive" comes form the Latin word infinitus, from in- (not) andfinitus (finished, limited).

You could say this actually makes sense: the infinitive describes an action, but unlike a regular verb, it is not limited in any way.

The regular verb is limited to the tense and subject. For example, in the sentence "Diana danced" the action is limited to Diana and to the past.

However, the infinitive is unlimited. In the sentence "To dance is easy", the action is not limited to any subject or to any time.

Infinitives are often used when actions are unreal, general, or future.

Examples:

(Note how the main underlined verb relates to unreal, general, or future actions.)

• Kate agreed to come.
• I hope to see you soon.
• We plan to finish this shortly.
• They decided to return home.
• She promised to stop smoking.
• We agreed never to talk about it again.
• He offered to sell the house.
• I refuse to pay!
• You seem to be disappointed.
• She asked him not to leave.
• I want to drink.
• They need to get up early.

Source : http://www.really-learn-english.com/gerunds-and-infinitives.html