B1 · Intermedio Capítulo 13

Rules, Advice, and Instructions

4 Reglas totales
48 ejemplos
6 min
Reglas en este capítulo Práctica rápida

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.

Lo que aprenderás

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.

Guía del capítulo

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.

Ejemplos clave (8)

1

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

Deberías probar la nueva cafetería del centro; sus lattes son increíbles.

Dar consejos y recomendaciones (Should)
2

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

Creo que deberíamos empezar nuestro proyecto temprano para evitar el estrés de última hora.

Dar consejos y recomendaciones (Should)
3

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

Debes entregar tu tarea antes del viernes.

Must: Obligación Fuerte y Necesidad
4

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

Debo recordar llamar a mis padres esta noche.

Must: Obligación Fuerte y Necesidad
5

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

Si tienes hambre, deberías tomar un aperitivo.

Primer Condicional para Consejos (should)
6

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

Si llueve más tarde, deberías llevar un paraguas contigo.

Primer Condicional para Consejos (should)
7

`If you feel cold, close the window.`

Si tienes frío, cierra la ventana.

Primer Condicional: Órdenes y Consejos (If + Imperativo)
8

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

Si tienes hambre, coge un aperitivo de la nevera.

Primer Condicional: Órdenes y Consejos (If + Imperativo)

Consejos y trucos (4)

💡

Suaviza tu Consejo

“Should” es para sugerencias suaves, no órdenes estrictas. Invita al acuerdo, no exige obediencia, haciendo tu consejo más fácil de aceptar.
You should consider it.
frontend.learn_grammar.from_rule: Dar consejos y recomendaciones (Should)
💡

Piensa en 'Obligación Fuerte'

Si puedes cambiar la frase por 'Es absolutamente necesario' o 'Es una regla que...', entonces must es tu mejor amigo. ¡Es mucho más fuerte que should!
You must complete this task by noon.
frontend.learn_grammar.from_rule: Must: Obligación Fuerte y Necesidad
💡

Presente Simple en 'If'

Siempre usa el present simple en la parte del if, aunque estés hablando de algo que pasará en el futuro. El sentido de futuro viene del should en la otra parte de la frase. Por ejemplo:
If you feel sick, you should see a doctor.
frontend.learn_grammar.from_rule: Primer Condicional para Consejos (should)
💡

Sé Directo con los Imperativos

Recuerda usar la forma base del verbo para tus órdenes o consejos. Evita añadir 'will' o 'should' en la cláusula principal, ya que cambia el significado a una predicción o sugerencia en lugar de una instrucción directa. Por ejemplo,
If you feel tired, rest
es una instrucción directa.
frontend.learn_grammar.from_rule: Primer Condicional: Órdenes y Consejos (If + Imperativo)

Vocabulario clave (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]

Errores comunes

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

Wrong: You should to study more.
Correcto: 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.
Correcto: 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.
Correcto: 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: ¡Habla con total seguridad sobre realidades y verdades constantes!

Práctica rápida (9)

¿Qué oración da un consejo correctamente?

Choose the correct sentence:

✓ Correct! ✗ Not quite. Correct answer: She should study harder for the test.
Should va seguido de la forma base del verbo (study), no studies. Must to es incorrecto; must no lleva 'to'.

frontend.learn_grammar.from_rule: Dar consejos y recomendaciones (Should)

Elige la forma correcta para completar la frase.

You ___ remember your passport for international travel.

✓ Correct! ✗ Not quite. Correct answer: must
Must es un verbo modal y va seguido de la forma base del verbo principal sin to ni «-s». ¡Es una regla importante al viajar!

frontend.learn_grammar.from_rule: Must: Obligación Fuerte y Necesidad

Elige la forma correcta para completar el consejo.

You ___ remember to save your work frequently.

✓ Correct! ✗ Not quite. Correct answer: should
Should se usa aquí para dar un consejo o una recomendación, indicando que es una buena idea guardar el trabajo a menudo.

frontend.learn_grammar.from_rule: Dar consejos y recomendaciones (Should)

Encuentra y corrige el error en la frase.

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 segunda cláusula debe ser un imperativo (orden directa) 'go to bed', no una predicción con 'will'.

frontend.learn_grammar.from_rule: Primer Condicional: Órdenes y Consejos (If + Imperativo)

Elige la forma correcta para completar el consejo.

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

✓ Correct! ✗ Not quite. Correct answer: should
Usamos should para dar consejos. Will predice un resultado, y can expresa habilidad.

frontend.learn_grammar.from_rule: Primer Condicional para Consejos (should)

Elige el verbo imperativo correcto para completar la frase.

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

✓ Correct! ✗ Not quite. Correct answer: tell
Después de la cláusula 'if', usamos la forma base del verbo para una orden directa.

frontend.learn_grammar.from_rule: Primer Condicional: Órdenes y Consejos (If + Imperativo)

Encuentra y corrige el error en la frase.

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.
Los verbos modales como must van directamente seguidos de la forma base del verbo principal. El to es incorrecto. ¡A corregir ese error antes del examen!

frontend.learn_grammar.from_rule: Must: Obligación Fuerte y Necesidad

Encuentra y corrige el error en la frase.

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.
En la cláusula if del Primer Condicional, usamos el presente simple. Por lo tanto, 'will arrive' es incorrecto; debe ser 'arrives'.

frontend.learn_grammar.from_rule: Primer Condicional para Consejos (should)

Encuentra y corrige el error en la oración.

Find and fix the mistake:

They should to call before visiting.

✓ Correct! ✗ Not quite. Correct answer: They should call before visiting.
Después del verbo modal should, el verbo principal siempre está en su forma base, sin 'to'.

frontend.learn_grammar.from_rule: Dar consejos y recomendaciones (Should)

Score: /9

Preguntas frecuentes (6)

Should significa principalmente que es una buena idea hacer algo, o que algo es generalmente esperado. Se usa para dar consejos, recomendaciones y sugerencias suaves. Piensa en ello como un empujón útil.
¡Claro que sí! Puedes usar should para hacerte auto-recomendaciones o reflexionar sobre lo que crees que es mejor para ti. Por ejemplo:
I should probably get some sleep
o
I should start that project soon.
R: Must se usa principalmente para expresar una obligación fuerte, una necesidad o una prohibición. Piensa en ello como un firme 'requerido' o 'no permitido'. Por ejemplo:
You must follow the rules.
R: No, must es un verbo modal, lo que significa que se comporta de manera diferente a los verbos regulares. No cambia de forma para diferentes sujetos o tiempos verbales. Por ejemplo, siempre es She must go, no She musts go.
Se trata de dar consejos o hacer recomendaciones sobre algo que es una situación real y posible en el futuro. Estás diciendo: 'Si X sucede, entonces deberías hacer Y.' Por ejemplo:
If you have a problem, you should talk to someone.
Un Primer Condicional normal con will predice un resultado seguro ('If it rains, we will stay home'). Con should, estás ofreciendo una sugerencia o consejo en su lugar ('If it rains, you should take an umbrella').
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