Modals of Necessity (must, have to and have got to)

How to express necessity or obligation? 

To express necessity or obligation we can use the modal verbs “must,” “have to” and “have got to”. 

• ·       Must is the strongest and most serious modal verb of the three and is most common in writing. It is unusual to use “must” in questions.I must study tonight. Is mean strong obligation there is no optional.
• ·       Have got to is most common in informal speech. It is not used in questions. I have got to study tonight. = I must study tonight.
• ·       Have to be the most commonly used modal of obligation and common in Informal and Formal. It is useful for forming questions and negatives.

Be careful! The subject and verb must agree for he/she/it subjects and the question form requires “Do/Does/Did”.

Example  of  have/has to	Question	Answer
I have to study tonight.	Do I have to study tonight?	Yes, I do.
She has to study tonight.	Does she have to study tonight?	No, she doesn't.

Remember: “have got to” and “have to” are modal verbs and require a simple verb to follow them. The “to” is part of the modal, it is not an infinitive “to”.

There is only one way to express past time with these modal verbs: HAD TO. (There is no past tense of must/have got to.)

For example:

Present Time	Past Time
We must show our passport at the airport.	Last night, we had to show our passport at the airport.
I have got to pay my phone bill soon.	I had to pay my phone bill this morning.
They have to go to the meeting today.	They had to go to the meeting yesterday.

Pronunciation notes:

The modal verb have got to is often contracted as: I've got to and sounds like “I've gotta...”

The modal verb have to often sounds like: “I hafta...” or “She hasta...”

“gotta”, “hafta”, and “hasta” cannot be used in written English. They are only used in speaking.

Question A…

1. Son: Mom, I don't want to clean my room. _________________ it right now?
   Mother: Yes, right now.
1.     Do I must clean
2.     Do I have to clean
3.     Have I to clean
2. In order to log on to the Internet, Sally __________ her user I.D.
1.      must enter
2.      has got to entering
3.      have to enter
3. Friend: _________________________ pay to see the doctor?
   Brother: No, she ________________ because she has medical insurance.
1.      Must your sister / mustn’t
2.      Do your sister have to / don't
3.      Does your sister have to / doesn't
4. When a police officer asks to see your driver's license, you _____________ to him/her.
1.      have got show it
2.      must to show it
3.      have got to show it
5. If you have a pet dog, you _____________ feed it every day or it will die!
1.      have got to
2.      has got to
3.      have got
6. Mr. Wu: Hi, Mark. Where's your dad?
   Mark: Oh, he ______________ to work because there was an emergency.
1.      had to go
2.      had got to go
3.      musted go
7. According to the law, drivers ______________ at stop signs.
1.      must stop
2.      must stopping
3.      must to stop
8. If Richard wants to become a professional musician, he ______________ every day.
1.       has to practice
2.       haves to practice
3.       have to practice

Question B…..

1. New drivers ……. take a test in order to get a driver's license. They have no choice.

2. A: …….  go to work today? B: No, I don't because it's Sunday.

3. John ……… finish the report quickly because the deadline is today at 4 pm.

4. A: Jennifer lost her passport. …… get a new one? B: No, she ……... She found it in her purse.

5. I'm sorry, Mom. I ……… call you back later. My cell phone battery is dying.

6. Canadians ……….. pay taxes every year. It's the law.

7. Sasha ….. email her homework to her teacher because she forgot to take it to class yesterday.

8. A: Does Joseph  …….. study very much tonight? B: No, he doesn't. He reviewed a lot last night and he understood everything well.

Good luck..