GERUNDS:
* The gerund can be used as subject of a sentence.
Living in Japan is expensive.
Smoking is bad for your health.
* Prepositions + gerund
He left without saying goodbye.
After having breakfast, she went to the office.
* After certain verbs such as admit, avoid, consider, deny, imagine, involve, miss, postpone, suggest, etc.
He admitted being jealous.
He is considering buying a country house.
Imagine yourself lying on the beach.
I miss riding my horse.
* After like, dislike, love, hate, enjoy (to talk about general preference)
I like painting.
I hate cooking.
INFINITIVES:
* Some adjectives are followed by TO + INFINITIVE
Able, afraid, angry, delighted, difficult, disappointed, easy, glad, happy, impossible, possible, sad, sorry, supposed, surprised.
They are delighted to see each other again.
You are supposed to come here at 8:00.
She was surprised to see her old friend.
It’s not possible to play football today.
* INFINITIVE OF PURPOSE.
To express purpose we can use to-infinitive.
She went to the supermarket to buy some meat.
He phoned Mary to tell her that she was ill.
Some verbs are followed by (OBJECT) + TO + INFINITIVE
Advise, allow, afford, agree, arrange, ask, decide, expect, forget, help, hope, invite, learn, manage, prefer, promise, refuse, regret, seem, teach, tell, want.
She decided to go to the party
I forgot to phone her.
They asked him to wait for a few minutes.
He seems to be a pleasant man.
I want to teach him to read.
He decided not to wait.