Which one of the following is correct spelling?

Being a cold day, we did not go out.

A cold day we did not go out.

It being a cold day, we did not go out.

It having a cold day we did not go out.

Every English sentence must have a verb

Every English sentence sentence should have a verb

Every English sentence has a verb

Every sentence has a verb

One of my friends are a lawyer

One of my friends is a lawyer

One of my friends is lawyer

One of my friends are lawyer

This is the tallest tree I have never seen

This tall tree I have never seen

This is the tallest tree I have ever seen

This tall tree I have ever seen

This is the tallest tree I have not yet seen

We discussed on the matter

We discussed about the matter

We discussed with the matter

We discussed in this matter

We discussed this matter