Subject (подлежащее)

To study English is difficult.

To buy a new car is important.

Part of the predicate (часть сказуемого)

The task is to study English.

The problem was to find the key.

Attribute (определение)

The book to read is very difficult.

The road to be built will be finished next year.

Object (простое дополнение)

I would like to drink something.

I want to come at 5 o’clock.

Adverbial modifier (обстоятельство)

In order to earn money, I worked hard last year.

To buy a flat, I worked hard.

Complex functions of the Infinitive:

Complex Object (сложное дополнение)

(to want, to expect, to consider, to know, to ask with TO)

I would like you (him, her, them, us) to drink something.

(to see, to watch, to hear, to feel, to make, to let without TO)

I saw her (him, them, you, us) cross the street.

He made me do it.

Complex Subject (сложное подлежащее)

The predicate is between the subject and the infinitive. It can be:

a) Passive is said, is known, is believed, is supposed

b) Active prove, seem, appear, turn out

c) Combination with “to be” is sure, is likely, is certain

He is said to study at the University.

He seems to work at a plant.

He is sure to become a good specialist.

They are known to have worked at this plant.

He is said to be translating the text now.

They are sure to be offered a good salary.