B1 · Intermédiaire Chapitre 13

Rules, Advice, and Instructions

4 Règles totales
48 exemples
6 min
Règles dans ce chapitre Pratique rapide

Chapter in 30 Seconds

Master the art of giving helpful advice and clear instructions with confidence.

  • Suggest better choices using the modal verb should.
  • Express non-negotiable rules and necessities using must.
  • Link specific conditions to advice and direct commands.
Command the room and guide others with precision.

Ce que tu vas apprendre

Feeling ready to give advice and strong instructions like a pro? This chapter will show you how to use if with commands and express what must be done, helping you guide others clearly and effectively in everyday conversations.

Learning Objectives

By the end of this chapter, you will be able to:

  1. 1
    By the end you will be able to offer polite recommendations for common problems using should.
  2. 2
    By the end you will be able to state firm legal or personal requirements using must.
  3. 3
    By the end you will be able to construct complex conditional sentences to give advice based on specific situations.

Guide du chapitre

Overview

As you continue your journey in B1 English grammar, you’re building the skills to connect with people and express yourself clearly in a wide range of situations. This chapter is all about giving effective English rules, advice, and instructions. Imagine being able to help a friend, offer clear guidance, or explain important steps without sounding aggressive or unclear.
That's exactly what you'll learn here!
We'll dive into the subtle art of using words like should to offer helpful recommendations, like
You should try that new cafe.
You'll also master must for those times when something is truly essential, as in
You must submit your report by Friday.
We’ll also explore how to combine these with the first conditional – using if clauses to give advice and commands that are relevant to specific situations, such as
If you want to pass the exam, you should study every day
or
If you see a problem, tell your manager immediately.
By the end, you'll be confidently guiding others and understanding important directions like a native speaker.

How This Grammar Works

Learning to give and understand rules, advice, and instructions effectively makes your English sound much more natural and confident. Let's explore how these pieces fit together, moving from gentle suggestions to strong directives.
First, for friendly advice and recommendations, we use should. This is your go-to for suggesting the best course of action without being too strong or bossy. For example,
You should drink more water
or
They should call their parents more often.
It implies a good idea, but the choice is still up to the listener.
When something is absolutely essential, a strong obligation, or a logical necessity, we use must. This isn't a suggestion; it's a rule, a requirement, or something that is highly certain. Think of signs like
All visitors must check in at reception
or personal vows like
I must finish this project tonight.
If there’s no other option, or the consequences of not doing it are serious, must is the word.
Now, let's add a condition! The first conditional for advice (should) combines a possible future situation with advice. The structure is simple: If + present simple, should + base verb.
This allows you to give advice that is specific and relevant to a particular scenario. For instance,
If you feel tired, you should take a break
or
If it rains tomorrow, we should bring umbrellas.
This makes your advice more practical and targeted.
Finally, we have the first conditional for commands & advice (If + Imperative). Here, instead of using should, you give a direct command or instruction in the second part of the sentence. The structure is: If + present simple, imperative (base verb form).
For example,
If you arrive late, wait outside
or
If you have any questions, ask the teacher.
This is perfect for giving clear, actionable instructions based on a potential future event. These structures together give you a powerful toolkit for guiding conversations and ensuring clarity in your interactions.

Common Mistakes

It's easy to mix up these useful phrases. Here are some common pitfalls and how to avoid them:
  1. 1✗ Wrong: You must try the new coffee shop. (Sounds too strong, like an order)
✓ Correct: You should try the new coffee shop. (A friendly recommendation)
*Explanation:* Use should for suggestions, not must, which implies a necessity or obligation.
  1. 1✗ Wrong: If you want to lose weight, you must to exercise. (Incorrect grammar with to)
✓ Correct: If you want to lose weight, you must exercise. (Correct verb form)
*Explanation:* After modal verbs like must or should, always use the base form of the verb without to.
  1. 1✗ Wrong: If it rains, you should to take an umbrella. (Incorrect grammar with to)
✓ Correct: If it rains, you should take an umbrella. (Correct verb form)
*Explanation:* Like with must, should is followed directly by the base verb form.

Real Conversations

Here’s how these grammar points appear in everyday chats:

A

A

"I'm really struggling with my English homework. It's so difficult!"
B

B

"Oh, really? If you're having trouble, you should ask the teacher for help during office hours. She's very approachable."
A

A

"My flight leaves at 6 AM tomorrow. I'm worried I'll miss it."
B

B

"Wow, that's early! You must set several alarms, and you should pack your bag tonight so you don't forget anything important."
A

A

"I'm going hiking this weekend, but the weather forecast looks a bit unpredictable."
B

B

If the weather changes suddenly, make sure you have a map and a fully charged phone. And if it starts raining heavily, turn back immediately!

Quick FAQ

Q

When should I use should versus must for advice?

Use should for advice, recommendations, or what's generally a good idea. It's a suggestion. Use must when there's a strong obligation, a rule, a necessity, or a strong personal conviction. It implies no real choice.

Q

Can I use if with must?

While grammatically possible (e.g.,

If you must leave, please close the door
), it's less common for *giving advice*. It usually expresses a resignation or necessity already acknowledged. For conditional advice, stick to should or an imperative.

Q

Is you should always polite?

Generally, yes, you should is polite. However, if used too frequently or with a lecturing tone, it can sometimes sound a little preachy. To soften it further, you can say

I think you should...
or
Perhaps you should...

Q

What's the difference between

If you want to...
and
If you need to...
when giving advice?

If you want to...
implies a personal desire or goal (e.g.,
If you want to improve, you should practice daily
).
If you need to...
implies a requirement or necessity (e.g.,
If you need to contact me, call this number
). Both are useful in conditional advice.

Cultural Context

In English, the way we give advice and instructions often reflects politeness and directness. While must clearly states an obligation, it can sometimes sound very direct, almost like an order, especially in informal contexts. Native speakers often prefer should or softer phrases (like
You might want to...
or I suggest you...) even for important advice, to maintain a friendly tone.
Using the first conditional with an imperative ("If you're cold, put on a jacket") is common and generally accepted as clear and direct, but still contextual. Understanding these nuances helps you sound more natural and avoid accidental rudeness.

Exemples clés (8)

1

You `should really try` the new coffee shop downtown; their lattes are amazing.

Tu devrais vraiment essayer le nouveau café en centre-ville ; leurs lattes sont incroyables.

Donner des conseils et des recommandations (Should)
2

I think we `should start` our project early to avoid any last-minute stress.

Je pense que nous devrions commencer notre projet tôt pour éviter le stress de dernière minute.

Donner des conseils et des recommandations (Should)
3

You **must** hand in your assignment by Friday.

Tu dois rendre ton devoir avant vendredi.

Must: Obligation Forte & Nécessité
4

I **must** remember to call my parents tonight.

Je dois penser à appeler mes parents ce soir.

Must: Obligation Forte & Nécessité
5

`If you're hungry, you should grab a snack.`

Si tu as faim, tu devrais prendre un en-cas.

Premier Conditionnel pour le Conseil (should)
6

`If it rains later, you should take an umbrella with you.`

S'il pleut plus tard, tu devrais prendre un parapluie avec toi.

Premier Conditionnel pour le Conseil (should)
7

`If you feel cold, close the window.`

Si tu as froid, ferme la fenêtre.

Premier Conditionnel: Ordres et Conseils (If + Impératif)
8

`If you're hungry, grab a snack from the fridge.`

Si tu as faim, prends un en-cas dans le frigo.

Premier Conditionnel: Ordres et Conseils (If + Impératif)

Conseils et astuces (4)

💡

Garde ça Doux

Should est là pour les suggestions douces, pas pour les ordres stricts. Ça invite à être d'accord, plutôt que d'exiger l'obéissance, rendant ton conseil plus facile à accepter. Pour une obligation forte, utilise must.
You should consider it.
frontend.learn_grammar.from_rule: Donner des conseils et des recommandations (Should)
💡

Pense "Obligation Forte"

Si tu peux remplacer par 'C'est absolument nécessaire de' ou 'C'est une règle que tu dois', alors must est probablement le bon choix. C'est bien plus fort que should.
You must finish this report today.
frontend.learn_grammar.from_rule: Must: Obligation Forte & Nécessité
💡

Présent simple dans la clause 'If'

Utilise toujours le présent simple dans la clause 'if', même si tu parles d'une possibilité future. Le sens 'futur' vient de 'should' dans la clause principale.
If you feel cold, you should wear a jacket.
frontend.learn_grammar.from_rule: Premier Conditionnel pour le Conseil (should)
💡

Reste direct avec l'impératif

Quand tu donnes un ordre ou un conseil, utilise la forme de base du verbe. N'ajoute pas will ou should, sinon le sens change ! Par exemple :
If you need help, ask.
frontend.learn_grammar.from_rule: Premier Conditionnel: Ordres et Conseils (If + Impératif)

Vocabulaire clé (6)

recommend to suggest something as a good choice mandatory required by law or rules passenger a person traveling in a vehicle instruction detailed information on how to do something prohibit to formally forbid something advice guidance or recommendations

Real-World Preview

plane

At the Airport Security

stethoscope

A Visit to the Doctor

Review Summary

  • Subject + should + Verb (base form)
  • Subject + must + Verb (base form)
  • If + Present Simple, Subject + should + Verb (base)
  • If + Present Simple, [Imperative Verb]

Erreurs courantes

Modal verbs like 'should' and 'must' are followed directly by the base verb. Never use 'to' after them.

Wrong: You should to study more.
Correct: You should study more.

In conditional advice, the second clause still needs a subject (you, he, she) before the word 'should'.

Wrong: If you are hungry, should eat.
Correct: If you are hungry, you should eat.

In the 'if' clause of a first conditional, we use the Present Simple, not 'will'.

Wrong: If you will see him, tell him the news.
Correct: If you see him, tell him the news.

Next Steps

You've taken a huge step toward fluency! Being able to guide others is a key leadership skill in any language. Keep practicing these patterns and you'll be a master communicator in no time.

Write 5 rules for your favorite sport using 'must' and 'should'.

Look at a recipe and identify the conditional instructions.

Continue to: Talking About Facts and Constant Truths

Pratique rapide (9)

Quelle phrase donne correctement un conseil ?

Choisis la bonne phrase :

✓ Correct! ✗ Not quite. Correct answer: She should study harder for the test.
'Should' est suivi de la forme de base du verbe ('study'), pas de 'studies'. 'Must to' est incorrect ; 'must' n'est pas suivi de 'to'.

frontend.learn_grammar.from_rule: Donner des conseils et des recommandations (Should)

Choisis le verbe impératif correct pour compléter la phrase.

`If you see a good movie playing, ___ me about it!`

✓ Correct! ✗ Not quite. Correct answer: tell
Après la clause if, on utilise la forme de base du verbe pour un ordre direct.

frontend.learn_grammar.from_rule: Premier Conditionnel: Ordres et Conseils (If + Impératif)

Choisis la bonne forme pour compléter la phrase.

You ___ remember your passport for international travel.

✓ Correct! ✗ Not quite. Correct answer: must
Must est un verbe modal et il est suivi de la forme de base du verbe principal, sans to ni «-s».

frontend.learn_grammar.from_rule: Must: Obligation Forte & Nécessité

Trouve et corrige l'erreur dans la phrase.

Find and fix the mistake:

`If you are tired, you will go to bed.`

✓ Correct! ✗ Not quite. Correct answer: If you are tired, go to bed.
La deuxième clause doit être un impératif (ordre direct) go to bed, pas une prédiction avec will.

frontend.learn_grammar.from_rule: Premier Conditionnel: Ordres et Conseils (If + Impératif)

Choisis la bonne forme pour compléter le conseil.

You ___ remember to save your work frequently.

✓ Correct! ✗ Not quite. Correct answer: should
'Should' est utilisé ici pour donner un conseil ou une recommandation, indiquant qu'il est bon de sauvegarder souvent son travail.

frontend.learn_grammar.from_rule: Donner des conseils et des recommandations (Should)

Trouve et corrige l'erreur dans la phrase.

Find and fix the mistake:

We must to study for the final exam.

✓ Correct! ✗ Not quite. Correct answer: We must study for the final exam.
Les verbes modaux comme must sont directement suivis de la forme de base du verbe principal. Le to est incorrect.

frontend.learn_grammar.from_rule: Must: Obligation Forte & Nécessité

Trouve et corrige l'erreur dans la phrase.

Find and fix the mistake:

They should to call before visiting.

✓ Correct! ✗ Not quite. Correct answer: They should call before visiting.
Après le verbe modal 'should', le verbe principal est toujours à sa forme de base, sans 'to'.

frontend.learn_grammar.from_rule: Donner des conseils et des recommandations (Should)

Trouve et corrige l'erreur dans la phrase.

Find and fix the mistake:

If she will arrive late, she should call us.

✓ Correct! ✗ Not quite. Correct answer: If she arrives late, she should call us.
Dans la clause 'if' du Premier Conditionnel, nous utilisons le présent simple. Par conséquent, 'will arrive' est incorrect ; ce devrait être 'arrives'.

frontend.learn_grammar.from_rule: Premier Conditionnel pour le Conseil (should)

Choisis la bonne forme pour compléter le conseil.

If you have a headache, you ___ take some medicine.

✓ Correct! ✗ Not quite. Correct answer: should
Nous utilisons should pour donner des conseils. Will prédit un résultat, et can exprime une capacité.

frontend.learn_grammar.from_rule: Premier Conditionnel pour le Conseil (should)

Score: /9

Questions fréquentes (6)

'Should' signifie principalement qu'il est bon de faire quelque chose, ou que quelque chose est généralement attendu. On l'utilise pour donner des conseils, des recommandations et de douces suggestions. Pense à cela comme un coup de pouce amical.
You should try this.
Absolument ! Tu peux utiliser 'should' pour te faire des auto-recommandations ou pour réfléchir à ce que tu crois être le mieux pour toi-même. Par exemple, 'I should probably get some sleep' ou 'I should start that project soon.'
R : Must est principalement utilisé pour exprimer une obligation forte, une nécessité ou une interdiction. Pense à un requis ou non autorisé très ferme. Par exemple :
You must complete the form.
R : Non, must est un verbe modal. Ça veut dire qu'il se comporte différemment des verbes réguliers. Il ne change pas de forme en fonction du sujet ou du temps. Par exemple : She must go.
Il s'agit de donner un conseil ou de faire une recommandation pour une situation réelle et possible dans le futur. Tu dis : 'Si X arrive, alors tu devrais faire Y.' "If you're tired, you should rest."
Un Premier Conditionnel 'normal' avec 'will' prédit un résultat certain ('If it rains, we will stay home'). Avec 'should', tu proposes une suggestion ou un conseil à la place ('If it rains, you should take an umbrella').
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Mastering Ability and Polite Requests
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Talking About Facts and Constant Truths
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