### Grammar

GRAMMAR FOCUS PREPOSITIONS

in | on | at | Note:
September | Monday | the moment | We don’t use in/on/at
spring | 15th of May | the weekend | this week next year last month every year
the morning | Sunday evening | 5 o’clock
2018 | Novruz holiday | night
the future | my birthday | midnight
the past | week days | lunchtime

Verb + ing | Verb + to/ing | Verb + to
enjoy stop finish suggest mind | start begin like love prefer | want need forget decide learn

Sample: Mehri suggested going to the park. (not suggested to go)

The modal verb have to

The Present Simple
I/You/We/They have to
He /She/It has to
The Past Simple
I/You/We/They had to
He/She/It had to
I have to learn these rules now.
She/he has to go to the party today.
We had to stay in London last week.
I/You/We/They don’t have to.
He /She/It doesn’t have to..
I/You/We/They didn’t have to.
He/She/It didn’t have to.
Do I have to learn these rules? Yes, I do.
Does she/he have to go ...? Yes, she does.
Did we have to stay ... ? Yes, we did.
I don’t have to learn the rules.
She doesn’t have to go there.
We didn’t have to go there.
He didn’t have to go there.
Modal Verbs

Must | Mustn’t | Should | Shouldn’t | Have to | Don’t have to
You must treat the old very politely. | You must not interrupt people while working. | You should show your card to a librarian. | You shouldn’t sleep late. | I have to help my friend. | You don’t have to climb the stairs.

Sample: We have to wait for him. We don’t have to wait for him.
(not we haven’t wait for him)
Mehri has to come to us. She doesn’t have to come to us). (not she hasn’t to come to us).