Modal Verbs for Advice: Should, Had Better or Must?

Priya Sharma

Priya Sharma writes English learning guides for ESL students. Pune-based language enthusiast.

Visual representation of the voice · not a photographic portrait

Quick answer: Use should for normal advice, had better for advice with a warning, and must only for very strong advice or rules. After any modal, use the base verb with no 'to', no '-s' and no '-ing': 'She should call', not 'She should to call'.↗ Share on X

To give advice in English without mistakes, use should for normal advice ("You should drink more water"), had better for advice with a warning ("You'd better leave now or you'll miss the bus"), and must only for very strong advice or rules. After all of these, put the base form of the verb: no "to", no "-s", no "-ing". So it is "She should call", never "She should to call" or "She shoulds call". Most mistakes with modal verbs come from breaking that one rule or from choosing a modal that is too strong for the situation.

What are modal verbs for advice?

READ ALSOPrepositions of Place: When to Use In, On and At in English →Could, Would or Can? Polite Modal Verbs for Work Requests →A, An or The? 7 Simple Rules to Pick the Right Article →

A modal verb is a small helper verb that changes the meaning of the main verb. It adds ideas like possibility, duty or advice. For advice, the most common ones are:

Think of it as a volume button. "Could" is quiet. "Must" is loud. Choosing the wrong volume is one of the most common problems, even for people whose grammar is otherwise good.

What is the number one grammar rule?

Modal verb + base form of the verb. Always.

The base form is the verb with nothing added: go, eat, call, study, be.

Two more things to remember:

1. Modals never change for he, she or it. There is no "shoulds", "musts" or "coulds".

2. Modals don't use "do" or "does" in questions or negatives. You don't say "Do I should...?" You say "Should I...?"

The only exception that looks strange is ought to. Here the "to" is part of the modal itself: "You ought to rest." But after "ought to", the verb is still in the base form: "You ought to rest", not "You ought to resting".

How do I ask for advice correctly?

READ ALSOIn, On, At for Time: Simple Rules With Everyday Examples →Careful or Carefully? Adjectives vs Adverbs in Daily English →Who, Which, or That? Relative Pronouns Made Simple for Talk →

Put the modal before the subject:

• "Should I take the job?"
• "What should I do?"
• "Where should we stay in Lisbon?"
• "Do you think I should apologize?" (here "do" goes with "think", not with "should")

Common mistakes:

In speech, people sometimes say "I should take the job?" with a rising voice. It is understood, but in writing and exams, use the correct question order.

How do I give negative advice?

Add not after the modal:

• You shouldn't (should not) eat so late at night.
• You ought not to drive when you're tired.
• You'd better not tell him yet.

The most common mistake is with "had better":

The word "not" comes after "better". Always.

What's the difference between "mustn't" and "don't have to"?

This one confuses many learners because in the positive, "must" and "have to" are similar. In the negative, they mean very different things.

Example:

• "You mustn't tell anyone my secret." (Please keep it quiet. It's important.)
• "You don't have to bring food. There will be plenty." (You can bring food if you want, but it's not needed.)

If you use "mustn't" when you mean "don't have to", you sound like you are forbidding something. That can be confusing or even a little rude.

When should I use "had better"?

"Had better" is not just stronger "should". It carries a warning: if you don't follow the advice, something bad will happen.

• "You'd better take an umbrella." (It's going to rain and you'll get wet.)
• "We'd better leave now." (Or we'll miss the train.)
• "You'd better not be late again." (Or there will be trouble.)

Three mistakes to avoid:

1. It's not about the past. Even though it uses "had", the meaning is about now or the future. "You'd better call her tomorrow" is correct.

2. Don't use it for general advice. "You'd better read more books" sounds like a threat. For general life advice, use "should": "You should read more books."

3. Be careful with people above you. Saying "You'd better sign this" to your boss sounds like an order with a warning. Use "You might want to sign this" or "Could you sign this?" instead.

In speech, people almost always use the short form: you'd better, we'd better, I'd better. Sometimes, in very casual speech, the "'d" almost disappears ("You better go"), but in writing, keep "'d" or "had".

Is "must" too strong for advice?

Often, yes. "Must" for advice is fine in two cases:

1. Strong recommendations about good things: "You must visit the old town. It's beautiful." Here "must" shows enthusiasm, not an order.

2. Serious situations: "You must stop smoking," from a doctor.

In most other situations, "must" sounds too strong. Compare:

• To a coworker: "You must change the title of the report." (sounds bossy)
• Better: "You should change the title." or "You might want to change the title."

A good habit: when in doubt, choose should. It is almost never wrong for advice.

How do I give advice about the past?

Use should have + past participle. This talks about something that was a good idea but didn't happen (or a bad idea that did happen).

• "You should have told me earlier." (You didn't tell me. That was a mistake.)
• "I shouldn't have eaten so much." (I ate too much. Now I feel bad.)
• "She ought to have checked the date."

Common mistakes:

"Should of" is a very common writing mistake, even among native speakers, because "should've" sounds like "should of". The correct form is always should have or should've.

Also note: "must have" is not past advice. "You must have told me" means "I'm sure you told me". It's about being sure, not about advice.

Are there other ways to give advice without modal verbs?

Yes, and they make your English sound more natural and polite:

• If I were you, I'd... "If I were you, I'd ask for a refund." (Use "were", not "was", in careful English.)
• Why don't you...? "Why don't you take a short break?"
• How about + -ing? "How about asking your teacher?" (Note the -ing, not the base form.)
• It might be a good idea to... "It might be a good idea to book early."
• I'd recommend + -ing or I recommend that you + base verb: "I'd recommend booking early." "I recommend that you book early."

Watch out for "recommend". These are wrong:

• "I recommend you to book early." (common, but not standard)
• "I recommend to book early."

Use "I recommend booking early" or "I recommend that you book early."

A quick self-check: can you spot the mistakes?

Read each sentence and find the problem. Answers are below.

1. You should to drink more water.

2. What I should wear to the interview?

3. You hadn't better be late.

4. He shoulds call his parents.

5. You should of asked me first.

6. You mustn't bring a gift, but you can if you want.

7. How about to take the bus?

Answers:

1. You should drink more water. (no "to")

2. What should I wear to the interview? (question order)

3. You'd better not be late. ("not" after "better")

4. He should call his parents. (no -s)

5. You should have asked me first. ("have", not "of")

6. You don't have to bring a gift, but you can if you want. (not necessary, not forbidden)

7. How about taking the bus? (-ing after "how about")

Your next step

Write five pieces of advice for a friend who is starting a new job. Use a different form in each one: should, ought to, had better, might want to, and "If I were you". Then check each sentence against two rules: base form after the modal, and the right strength for the situation. Read them out loud. Tomorrow, write three sentences about mistakes you made in the past using "should have" and "shouldn't have".

FAQ

Is it correct to say 'should to'?

No. After should, use the base form of the verb: 'You should study', not 'You should to study'. Only 'ought to' includes 'to'.

What is the negative of 'had better'?

'Had better not' or 'you'd better not'. The word 'not' always comes after 'better', so never say 'you hadn't better'.

What is the difference between mustn't and don't have to?

'Mustn't' means something is not allowed. 'Don't have to' means it is not necessary, so you can choose.