Grammar

Pr. S.
People celebrate New Year all live.
People don't celebrate New Year all live.
Do people celebrate New Year all live?

P. S.
People celebrate New Year one year ago.
People didn't celebrate New Year one year ago.
Did people celebrate New Year one year ago?

F. S.
People will celebrate New Year on monday.
People will not celebrate New Year on monday.
Will people celebrate New Year on monday?

Pr. C.
People are celebrating New Year at this moment.
People aren't celebrating New Year at this moment.
Are people celebrating New Year at this moment?

P. C.
People were celebrate New Year.
People weren't celebrate New Year.
Were people celebrate New Year?

Pr. P.
People have celebrate New Year.
People haven't celebrate New Year.
Have people celebrate New Year?

Cond. 1
If  people celebrate New Year, you will enjoy it.

Cond. 2
If  people didn't celebrate New Year, 100 years ago, you wouldn't have fun.

Cond. 3
If people didn't celebrate New Year, you wouldn't have new friends.