Functions of infinitive phrase:

1- Subject:     

To learn a new language is challenging.

To be honest all the time is not easy.

To furnish our home took a lot of time.

For her to clean the house every day is absolutely necessary.

*It is possible to start these sentences with False “It” and place the true subject after the verb.

 It is challenging to learn a new language.

It is not easy to be honest all the time.

It took a lot of time to furnish our home.

It is absolutely necessary for her to clean the house every day.

 NB: IT + to be + Adjective + for / of / to + noun / pronoun + Infinitive

It is easy/difficult for …………

It is foolish/impertinent/polite/proper/rude/stupid/wicked/wise/kind/good/intelligent/unworthy/generous of ….

It is alarming/amazing/disappointing/embarrassing/irritating/shocking to …

He had only one desire – for his family to be in good health.

(in order ) for me to buy a car, I’ll have to take a loan from the bank.

 ۲- Subject Complement (after to be):

My goal is to get good grades.

Her job last summer was to answer the phones.

The regulation is for boys and girls to live in separate

 ۳- Direct Object: (Verb + to) / (Verb + object + to) / (Verb + to + object)

She refused to tell the …

She pretended to …

Her husband wants her to clean the house every day.