Grammar · Free lesson
Should or must? Separate advice from a requirement
You are helping someone prepare for a workshop. Bringing a notebook would be useful, but it is optional. Wearing safety glasses is a rule of this particular workshop. Your message needs to keep those two expectations separate.
Professor Scott MendozaMeaning in this lesson
should and must
Modal verbs that can help distinguish advice from a strong requirement.
Example
“You should bring a notebook, and you must wear safety glasses in the workshop.”
The notebook is recommended. The glasses are required by the workshop rule.
The short answer
Should often gives advice: “You should bring a notebook.” Must can express a requirement: “You must wear safety glasses in this workshop.” Both take the base form of the next verb, without to. Choose the form that matches the real expectation.
Make the strength of the message match the situation.
Should recommends an action. Must presents an action as necessary or required in the situations taught here. Say should bring and must wear, not should to bring or must wears. The speaker and context matter: using must does not turn a personal opinion into a law.
Explain the two expectations.
Do I need a notebook and safety glasses?
You should bring a notebook for your notes. You must wear safety glasses inside; that’s our workshop rule.
The context makes the notebook optional and the glasses required. The modal verbs carry that distinction into the message.
Choose the right strength
Identify advice
A notebook would be helpful: You should bring one.
Identify a requirement
The workshop requires glasses: You must wear them.
Use the base verb
Should bring; must wear. Do not add to or an -s ending.
Try it now
Check what you’ve learned.
Read all answers and explanations
A notebook is optional but useful. Which sentence presents bringing it as advice?
You should bring a notebook.Should presents the notebook as a recommendation. The first option incorrectly describes it as required; the third describes the past.
The workshop rule requires safety glasses. Which sentence clearly communicates that requirement?
You must wear safety glasses inside.Must wear communicates the stated requirement. The other sentences do not tell the visitor what is required now.
Choose the correct modal-plus-verb form.
She should bring a notebook.Use the base form bring after should. Do not add to or change bring to brings after the modal.
Put it into practice
Fix an overstrong workshop message.
A notebook is optional and recommended. Safety glasses are required. Change the notebook wording so it gives advice, and preserve the glasses requirement.
You must bring a notebook, and you must wear safety glasses.
See a model answer
You should bring a notebook, and you must wear safety glasses.
The first draft was grammatical, but it overstated the notebook expectation. Accurate grammar includes choosing wording that matches the facts.
A little more clarity
Common questions
A few useful details before you move on.
Does must always describe an official rule?
No. It can express a speaker’s strong view of what is necessary, or even an enthusiastic recommendation. Use the context to understand the force of the message.
“You must try this cake!” is usually an enthusiastic recommendation.
Does the verb change after should with he or she?
No. The verb after should stays in its base form, regardless of the subject.
“I should check.” / “She should check.”
Take it into your day
Do not turn an optional suggestion into a requirement. Check the actual expectation, then use should or must and the base verb.
Your next step · Available on Udemy
Choose English that matches your intention.
Advice and requirements are one useful contrast. The English Grammar and English Speaking course builds a wider grammar foundation through explanations, examples, conversations and practice you can return to.
Explore the course English Master Course: English Grammar and English Speaking