1. The gerund (verbo + -ing form) is generally used as the subject of a sentence.

Smoking in public places is prohibited.
Denying your own faults is very common.

You can also have the structure : it is + adjective + the infinitive.

It is prohibited to smoke in public places.
It is very common to deny your own faults.

2. It is also used as the object of certain verbs (admit, advise, appreciate, avoid, consider, deny, dislike, enjoy, finish, give up, imagine, keep, mind, postpone, prevent, quit, recall, recommend, resent, risk, suggest, tolerate, among others.)

I dislike having a dog.

We can also use the possessive before the gerund.

I dislike Mark’s having a dog.
I dislike his having a dog.

In informal spoken English some people use object pronouns (him, her, them) instead of possessives before the gerund.

I dislike him having a dog.

3. Some verbs can be used with the infinitive (agree, appear, ask, attempt, begin, can’t afford, can’t wait, choose, consent, expect, fail, hesitate, learn, manage, mean, need, offer, pay, plan, prepare, pretend, promise, refuse, seem, struggle, swear, want, wish, among others).

a. verbs followed by the infinitive

I hope to pass my Spanish test.
He swore not to tell anyone our secret.

b. verbs followed by an object and the infinitive.

He persuaded them to come here.
I need you to go to the store for me.
She warned us not to do that.

c. verbs that have or don’t have an object and the infinitive.

He asked to come to the party.
He asked me to open the door.

Do you want to go to the movies later on?
Do you want me to go to the store for you?

Soon we’ll have part II, ok?

This is it for today, take care!