Using modal verbs to give order and advice is a piece of cake. You decide how strong you want to give the advice and pick the right modal verb. Here’s how to do it.
Modal verbs to give order and advice
To express obligation in giving order and advice, we use these modal verbs :
- must
- had better
- should/ought to
- could
The expression could be strong to less strong as :
1. Must
Use “must” when :
- giving someone an order or strong obligation to do something
- you feel very strongly about that order
- there will be high consequence if that order is not done
For example :
You must take this medicine twice a day.
We must arrive on time for his reception or he’ll get furious.
You must not forget to take down the old advertisement or they will charge us more money.
(This is an order to not forget taking down the old advertisement, not an advice.)
We can use “must” to say the right thing to do :
I must try harder not to get distracted all the time.
2. Had better
Use “had better” to give strong or urgent advice that can have negative consequences if it’s not followed. It means if you don’t follow the advice, you’ll regret it.
We also use “had better” to talk about the right thing to do. Like a common sense.
For example :
You had better leave for work. It’s already 8.00.
You’d better start now. You have one hour left to submit that essay.
(had better = ‘d better)
You’d better not forget to register today. The registration deadline is at 4 p.m.
(We normally use had better not for negative meaning. In this case : forget to register.)
She’d better be here in 15 minutes or she won’t make it to the meeting with the manager.
Maria had better go and apologize to him.
(We tell Maria the right thing to do.)
I’d better go to sleep now. It’s already late.
3. Should/ought to
When you want to give strong advice, use “should/ought to”. “Ought to” is a more formal and less common way to say “should”.
For example :
It’s too hot outside. You should wear a hat.
You should buy this shirt. It looks good with your sneakers.
You shouldn’t drive tonight. It’s pouring outside.
(We normally use shouldn’t for negative meaning. The negative meaning here : driving at night when it’s pouring.)
You shouldn’t wear that skirt for your speech. It’s too short.
Should I leave now? I still have 30 minutes before class.
Which class should I have first? French or Spanish?
(We may use “should” to ask for advice.)
We ought not to have ordered so much food.
(The negative of “ought to” is not common. We usually use shouldn’t or should not instead.)
Use “should have” and “ought to have” to talk about the past to give advice about the right thing to do.
For example :
You should have / ought to have accepted his offer.
You shouldn’t have worn those shoes.
They shouldn’t have made any noise during the seminar.
4. Could
Use “could” to suggest one or two possible pieces of advice. It’s not necessary to follow that advice.
For example :
You could study science or engineering at college. You’re good at both of them.
You could prepare soup or noodles for dinner. We’re not picky eaters.
Your car is too old. You could get a new one.
How to form the order and advice
Like other auxiliary verbs, modal verbs generally :
- come before the main verb in affirmative and negative sentences without to (except ought to)
- are immediately followed by not in the negative sentences
- never change in any kind of sentences
- come immediately before the subject in questions
Here’s how to form the order and advice with modal verbs :
Which modals you should use
Choose the appropriate modals — must, had better, should / ought to, or could — based on your objective and the level of emphasis you want to convey. Your choice depends on how you look at the situation.
Try to compare these sentences :
1. You really must start looking for a job. Your debt is due this month.
(Say this to someone who’s not actively looking for a job. Obligate them to start doing it. You know unpaid debt will cause serious consequences. And it’s urgent.)
2. You had better start looking for a job or a debt collector will come to your house.
(The debt may be due in a few months and you absolutely know there will be consequences.)
3. You should/ought to start looking for a job.
(Someone has just got fired and you suggest an action.)
4. You could start looking for a job.
(In response to news about potential downsizing at the office, you offer precautionary advice to find another job.)
Common mistakes
Don’t use mustn’t or couldn’t when giving advice.
“Must” is for giving stronger advice, but “must not” is for obligation/order. It expresses something is not allowed.
For example :
You must not enter that jungle. It’s dangerous.
(Entering the jungle is not allowed.)
“Could” is for giving advice, but “could not” means inability in the past and also for imperative.
For example :
You could buy a hat or an umbrella for this sunny day.
(This is advice.)
She could not buy a jacket for this sunny day.
(The person you talk about may not have the money to pay for the jacket.)
You could not talk harshly to your parents. Have some respect.
(You give moral imperative to someone.)
If you are currently studying modal verbs and how to use them, here are some other use of modal verbs :
Modal Verbs : How to Express the Ability
Modal Verbs: How to Ask for Permission and Make Requests
Grammar book reference
DK. English for Everyone: English Grammar Guide: A Comprehensive Visual Reference. DK Publishing (Dorling Kindersley), 2016.
Thomas, Barbara, et al. Grammar and Vocabulary for First and First for Schools Book with Answers and Audio. Cambridge University Press, 2015.
What can I do for you?
Did I miss something on this topic? Or you know another common mistake that we make when giving advice? Connect with me and let me hear your best advice!
I occasionally update this article, so subscribe here to receive more updates.
If you have any doubts, just let me know!