- I have bought a table; it is made of teakwood.
- The dog is ill; it should be taken to the hospital.
It is often used to refer to a young child. This is particularly common when the sex of the child is not mentioned.
- The baby cried because it was hungry.
It can be used to refer to some statement in the preceding clause.
- He created the trouble; and he knows it.
- He was telling a lie; and he knew it.
It can be used as impersonal pronoun.
- It is raining.
- It has been snowing for hours.
Note that it is also used in speaking of the weather or the time.
- It is fine weather now.
- It is time they started work.
It can be used to refer back to a collective noun when it is viewed as a single unit.
- The committee has decided to hold its next meeting on the 25th.
- The jury gave its verdict.
We do not use it to refer back to a collective noun when it is used to refer to the separate members. Instead we use they.
- The committee were divided in their opinion. (NOT The committee were divided in its opinion.)
Note also the use of the plural verb.