1. Overview & Concept
- What is it? Should and shouldn't (should not) are modal verbs used to give advice, express recommendations, and state weak obligations or expectations.
- Purpose: We use should to say what is the right or best thing to do in a situation — it is less strong than must. It is the most common modal for giving and asking for advice.
2. Structure & Formula
Affirmative:
Subject + should + base verb
| Subject | Modal | Base Verb | Rest |
|---|---|---|---|
| I / You / He / She / It / We / They | should | see | a doctor. |
Negative:
Subject + shouldn't / should not + base verb
| Subject | Modal | Base Verb | Rest |
|---|---|---|---|
| I / You / He / She / It / We / They | shouldn't | eat | so much sugar. |
Question:
Should + subject + base verb?
| Modal | Subject | Base Verb | Rest |
|---|---|---|---|
| Should | I | call | him now? |
Short answers:
- Yes, you should. / No, you shouldn't.
Key grammar rules:
- Should never changes form — no -s, -ed, or -ing.
- Always followed by a bare infinitive.
- Should is the same for all persons.
3. Usage Rules
- Rule 1 — Advice: Use should to recommend what someone ought to do.
- You should see a doctor about that cough.
-
You shouldn't drink coffee before bed.
-
Rule 2 — Moral obligation / weak duty: Use should when something is the right or proper thing to do, but it is not a legal requirement.
- People should help each other.
-
You should apologize for what you said.
-
Rule 3 — Asking for advice or recommendations: Use should in questions to ask what is advisable.
- What should I wear to the interview?
-
Should we take the train or the bus?
-
Rule 4 — Expectation (something is likely or expected): Use should to say something is expected to happen or be true.
- The parcel should arrive by Friday.
- It should be warm enough to go to the beach.
Comparison table — Should vs. Must:
| Should | Must | |
|---|---|---|
| Strength | Weak obligation / advice | Strong obligation / necessity |
| Example | You should exercise. | You must wear a seatbelt. |
| Consequence of not doing | Generally no legal/severe consequence | Usually a rule; may have legal/serious consequence |
4. Signal Words & Context Clues
- Advice context: in my opinion, I think, it would be good to, it would be better to.
- Expectation context: probably, by then, by now, I expect.
- Questions seeking advice: What do you think I…? Do you think I…?
5. Common Pitfalls & Mistakes
- ❌ She shoulds go. → ✅ She should go. (No -s on modal verbs.)
- ❌ You should to eat more vegetables. → ✅ You should eat more vegetables. (No to after modal.)
- ❌ Should you speaking now? → ✅ Should you speak now? (Bare infinitive.)
- ❌ I don't should go. → ✅ I shouldn't go. (Negative of should is shouldn't / should not; not don't should.)
- ❌ Using should with the same strength as must: You should stop immediately is softer than You must stop immediately. Don't use should when a rule is mandatory.
6. Real-World Examples
- You should drink at least eight glasses of water a day.
- I think you shouldn't tell him the bad news right now.
- Should I book the tickets in advance?
- Students should read all the chapters before the exam.
- You shouldn't drive if you're tired.
- The meeting should finish by 5 o'clock.
- She should apologize — what she did was wrong.
- You should try the seafood here — it's delicious.
- We shouldn't waste food.
- Should I wear formal clothes for the party?
7. Summary Table
| Meaning | Modal | Example |
|---|---|---|
| Advice (positive) | should | You should rest. |
| Advice (negative) | shouldn't | You shouldn't smoke. |
| Weak moral obligation | should | People should be kind. |
| Expectation | should | The bus should arrive soon. |
| Asking for advice | should | What should I do? |