Press Firmly, and You Mustn't Use Ice: Imperatives and Modals of Advice and Obligation – First Aid (Senior 4 English) | Ganzaa

First Aid

Lessons

Senior 4 · English

First Aid

5 lessons

Lesson 3 of 5

Press Firmly, and You Mustn't Use Ice: Imperatives and Modals of Advice and Obligation

25 min

Let's begin

First aid English has its own grammar. It gives orders (Press firmly), it gives advice (You should take a course), it states rules (You must wear gloves), it forbids (You mustn't use ice), and it says what is not necessary (You don't have to be a doctor). Each of these jobs has its own form, and mixing them up can change a safe instruction into a dangerous one. This lesson sorts them out.

A model text: the school first aid team's card

Written by Ganzaa for an imagined school first aid team. Imperatives are in bold; modal verbs are underlined.

Our first aid team: rules and advice

Rules. Team members must complete a certified first aid course before they join. You have to sign the first aid book every time you help someone, because the school needs a record. You mustn't give anyone medicine: that is the nurse's job.

At an emergency. Check that the scene is safe. Shout for help and call 112 or 912. Don't move anyone who has fallen from a height. Never leave an unresponsive person alone.

Advice. You should keep your phone charged during school hours. You ought to practise the recovery position every term. If you see a burn, you'd better start cooling it at once, or it will get worse. You don't have to be a doctor to help: you just need to stay calm and follow the steps.

1 Imperatives: giving instructions

Form	Example	Use
base verb	Press firmly on the wound.	a direct instruction
don't + base verb	Don't use ice.	a negative instruction
always / never + base verb	Never leave an unresponsive person alone.	a rule for every time
do + base verb	Do call 912 if you're not sure.	strong emphasis or encouragement
let's + base verb	Let's practise the recovery position.	a suggestion that includes the speaker

In an emergency, imperatives are not rude: they are clear. In everyday requests, soften them with please or a question (Could you pass the gloves?).

2 Advice

Form	Example	Notes
should / shouldn't + base verb	You should take a first aid course.	the most common way to advise
ought to + base verb	You ought to practise every term.	the same as should, a little more formal; the negative ought not to is rare
had better ('d better) + base verb	You'd better cool it now, or it will blister.	stronger: a warning that something bad will happen if you don't; about now, not the past
it's best to / why don't you …?	It's best to lean forward.	softer, friendly advice

3 Obligation, prohibition and no obligation

Meaning	Form	Example
Strong obligation: the speaker or a written rule decides	must + base verb	Team members must complete a course.
Obligation from outside: a rule, law or situation	have to / has to; past: had to; future: will have to	We had to call an ambulance.
Necessity	need to	You need to stay calm.
Prohibition: it is wrong or not allowed	mustn't; be not allowed to	You mustn't give medicine.
No obligation: it is not necessary (but allowed)	don't have to; needn't; don't need to	You don't have to be a doctor.

The most important contrast: You mustn't move him = don't move him! You don't have to move him = moving him is not necessary, but you may if you need to. In first aid, confusing the two can hurt someone.

4 Looking back: had to and should have

Past obligation: must has no past form; use had to. We had to wait twenty minutes for the ambulance.
Criticism or regret about the past: should have / shouldn't have + past participle. They shouldn't have tilted his head back. They should have asked him to lean forward.

Pronunciation: mustn't is /ˈmʌsnt/, with no first t; ought to is /ˈɔːt tə/; in fast speech should have sounds like /ˈʃʊdəv/, but it is never written "should of".

Worked example 1: choosing the modal from the situation

"You ___ give her water; she's not fully awake." Giving water could make her choke: it is forbidden, not just unnecessary. mustn't.
"You ___ wear a uniform to join the first aid team." Nobody requires it: it is not necessary. don't have to.
"The rules say every helper ___ sign the book." An outside rule creates the obligation. has to (or must in the written rule itself).
"It's starting to swell. You ___ take that ring off now, or you won't be able to." Advice with a warning of a bad result: 'd better.

Worked example 2: what went wrong? Using should have

Situation (from Lesson 2): When a girl fainted at assembly, everyone stood around and nobody did anything.

Find what was done wrongly or not done: nobody helped her down; nobody laid her down or raised her legs; nobody checked for injuries.
Use should have + past participle for each missing action: Someone should have helped her down gently. They should have laid her on her back and raised her legs.
Use shouldn't have for each wrong action: Everyone shouldn't have just stood around.
End with advice for next time, in the present: Next time, we should know the steps, and the school ought to train a first aid team.

Warning

No to after must, should, had better: You must to wear gloves. You'd better to hurry. But ought to, have to, need to keep it.
No -s after modals: She musts call. He shoulds wait. But he has to.
Had better is about now or the future, even though it looks past: You'd better go now. Its negative is had better not: You'd better not move him.
Write should have, never "should of".

Tip

"Mustn't" stops you; "don't have to" frees you. If the sentence would make a good warning sign (DO NOT …), you need mustn't. If it would make a relieved sigh (Oh good, it's not necessary), you need don't have to.

How to Use Should, Ought to, Supposed to and Had Better, Oxford Online English (about 14 minutes, 2017). Listen for how 'had better' differs from 'should', and for the past forms the teacher uses to criticise.

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Practice

Make imperatives from this advice: (a) It is a good idea to lean forward. (b) It is a mistake to put butter on a burn. (c) It is a rule that you check for danger every time.
Choose mustn't or don't have to: (a) You ___ remove the first pad from a bleeding wound. (b) You ___ have special equipment to help someone who has fainted. (c) You ___ put your fingers into the mouth of a choking person. (d) You ___ call 912 for a small cut that has stopped bleeding.
Complete with should, had better, must or has to: (a) The burn is blistering. You ___ get it checked today. (b) Every school ___ keep a first aid kit, according to our rules. (c) You ___ learn first aid; it's a useful skill. (d) Visitors ___ sign in at the gate.
Correct: (a) She musts call the nurse. (b) You'd better to cool it. (c) They should of called 912. (d) We must to wait yesterday.
Write four sentences about the coach's nosebleed story in Lesson 2, using should have and shouldn't have.
Write a set of six rules and pieces of advice (about 80 words) for a first aid corner in your classroom. Use at least two imperatives, must, mustn't, should and don't have to.

Show answersHide answers

(a) Lean forward. (b) Don't put butter on a burn. (c) Always check for danger.
(a) mustn't (b) don't have to (c) mustn't (d) don't have to.
(a) had better (warning) or should (b) has to (or must) (c) should (d) must (or have to).
(a) She must call the nurse. (b) You'd better cool it. (c) They should have called 912. (d) We had to wait yesterday.
Models: The players shouldn't have told him to lie on his back. He shouldn't have looked up at the sky. They should have sat him down and asked him to lean forward. Someone should have pinched the soft part of his nose for at least ten minutes.
Answers will vary.

Quick check

You ___ use ice on a burn: it deepens the injury.

Key points

Imperatives give clear instructions: Press. Don't use ice. Never leave them alone.
Advice: should, ought to; had better adds a warning.
Obligation: must (speaker or written rule), have to (outside rule; past had to). Prohibition: mustn't. No obligation: don't have to, needn't.
Past criticism: should have / shouldn't have + past participle.

Sources and credits

First aid team card (school and team imagined), decision tree, grammar tables, worked examples and practice written by Ganzaa. The first aid content follows the guidance credited in Lessons 1 and 2.
Video: How to Use Should, Ought to, Supposed to and Had Better, Oxford Online English, embedded from YouTube.

1A model text: the school first aid team's card

21 Imperatives: giving instructions

32 Advice

43 Obligation, prohibition and no obligation

54 Looking back: had to and should have

A model text: the school first aid team's card

1 Imperatives: giving instructions

2 Advice

3 Obligation, prohibition and no obligation

4 Looking back: had to and should have