to be - function in the sentence

Identify the function of the verb “to be” in the sentence:

He is my uncle.

Identify the function of the verb “to be” in the sentence:

We are having dinner now.

Identify the function of the verb “to be” in the sentence:

The car is repaired every month.

Identify the function of the verb “to be” in the sentence:

She is to arrive at 5 o'clock.

Identify the function of the verb “to be” in the sentence:

I am happy with my new job.

Identify the function of the verb “to be” in the sentence:

They are building a new house.

Identify the function of the verb “to be” in the sentence:

The work is finished by Friday.

Identify the function of the verb “to be” in the sentence:

You are to wait here.

Identify the function of the verb “to be” in the sentence:

She was at the hospital.

Identify the function of the verb “to be” in the sentence:

We are watching a comedy.