Topics
BeginnerModals
How modal verbs express possibility, obligation, permission and ability in Spanish, English and Chinese.
Compare languages
English uses a closed set of modal verbs that never change form. Spanish uses conjugated verbs with subjunctive. Chinese uses auxiliary verbs like 会, 能, 可以, 要, 应该 before the main verb.
Overview
Modal verbs express attitudes toward an action — possibility, necessity, permission, ability, and advice.
- Spanish: Uses conjugated verbs (poder, deber, querer) that inflect for person and tense. The subjunctive is required for many modal expressions.
- English: Uses a small, closed set of invariable modals (can, could, may, might, must, shall, should, will, would). They never change form.
- Chinese: Uses auxiliary verbs (会, 能, 可以, 要, 应该) placed before the main verb. They do not conjugate.
Spanish
Spanish modals are fully conjugated verbs that require specific grammar depending on meaning.
Poder (can, may)
| Tense | Form | Example |
|---|---|---|
| Present | puedo, puedes, puede | No puedo nadar. (I can’t swim.) |
| Past (pret) | pude, pudiste, pudo | No pude venir. (I couldn’t come.) |
| Past (imp) | podía | No podía verlo. (I couldn’t see him. — ongoing) |
| Subjunctive | pueda, puedas, pueda | Espero que pueda venir. (I hope I can come.) |
| Conditional | podría | ¿Podrías ayudarme? (Could you help me?) |
Deber (must, should, ought to)
- Debes estudiar. (You must study. — strong obligation)
- Deberías descansar. (You should rest. — advice)
- No debes fumar. (You must not smoke. — prohibition)
Important: Deber de + infinitive indicates probability, not obligation:
- Debe de ser tarde. (It must be late. — deduction)
- Debe ser honesto. (He must be honest. — obligation)
Querer (want, will)
- Quiero ir. (I want to go.)
- No quiero ir. (I don’t want to go.)
- Querría un café. (I would like a coffee.)
Future with ir a
Spanish often uses ir a (going to) for near future:
- Voy a estudiar. (I’m going to study.)
- Va a llover. (It’s going to rain.)
Subjunctive in modal expressions
Many Spanish modals trigger the subjunctive:
- Es posible que llueva. (It may rain.)
- Quiero que vengas. (I want you to come.)
- Es necesario que estudies. (It’s necessary that you study.)
English
English has nine core modal verbs: can, could, may, might, must, shall, should, will, would. They are invariable — they never change for person or tense.
Can / could (ability, permission, possibility)
- Ability: I can swim. (present) / I could swim when I was young. (past)
- Permission: Can I go? (informal) / May I go? (formal)
- Possibility: It can get cold at night. / It could rain tomorrow.
Must / have to / should (obligation, advice)
| Strength | Example | |
|---|---|---|
| must | Strong obligation (internal) | I must finish this. |
| have to | Strong obligation (external) | I have to pay taxes. |
| should | Advice / recommendation | You should rest. |
| ought to | Advice (more formal) | You ought to apologize. |
| need to | Necessity | You need to see a doctor. |
Will / would (future, volition, habit)
- Prediction: It will rain.
- Willingness: I will help you.
- Habitual past: He would always sing.
- Polite request: Would you help me?
No conjugation
English modals never add -s, -ed, or -ing:
- ✅ He can swim.
- ❌ He cans swim.
- ❌ He canning swim.
Negative modals
Negation is added directly to the modal:
- I cannot swim. / I can’t swim.
- You must not smoke. / You mustn’t smoke.
- He should not leave. / He shouldn’t leave.
Chinese
Chinese modals are auxiliary verbs placed before the main verb. They do not conjugate.
会 (learned skill / prediction)
- 我会说中文。(I can speak Chinese. — learned ability)
- 明天会下雨。(It will rain tomorrow. — prediction)
能 (physical ability / possibility)
- 我能吃十个包子。(I can eat ten dumplings. — physical capacity)
- 现在能走了。(Now I can walk. — possibility after injury)
Rule: 能 implies circumstances allow it; 会 implies skill or prediction.
可以 (permission / possibility)
- 我可以进来吗？(May I come in? — permission)
- 这个可以吃。(This is edible. — possibility)
要 (want / need / future intention)
- 我要喝水。(I want to drink water.)
- 我要去北京。(I’m going to Beijing. — intention)
- 你要小心！(You need to be careful!)
应该 (should / ought to)
- 你应该早点睡觉。(You should go to bed early.)
- 应该不会下雨。(It probably won’t rain. — deduction)
必须 (must)
必须 expresses strong obligation:
- 你必须完成作业。(You must finish your homework.)
可能 (possible / may)
可能 expresses possibility, placed before the verb:
- 他可能不来。(He might not come.)
Comparison at a glance
| Meaning | Spanish | English | Chinese |
|---|---|---|---|
| Ability | puedo | can | 能 / 会 |
| Learned skill | sé | can | 会 |
| Permission | puedes | may / can | 可以 |
| Possibility | puede que | may / might | 可能 |
| Strong obligation | debo / tengo que | must / have to | 必须 / 要 |
| Advice | deberías | should / ought to | 应该 |
| Future intention | voy a / hablaré | will / going to | 要 / 会 |
| Prohibition | no debes | must not / cannot | 不能 / 不可以 |
| Form changes | Yes (conjugated) | No (invariable) | No (invariable) |
Examples
In Context
| Spanish | English | Chinese |
|---|---|---|
| ¿Puedes nadar? | Can you swim? | 你会游泳吗？ |
| Deberías descansar. | You should rest. | 你应该休息。 |
| Puede que llueva. / Puede llover. | It may rain. | 可能会下雨。 |
| Debo irme. / Tengo que irme. | I must go. / I have to go. | 我必须走了。 |
Common mistakes
-
Spanish speakers learning English: Conjugating modals: He cans swim → He can swim
-
English speakers learning Spanish: Forgetting subjunctive: Es posible que llueve → Es posible que llueva
-
English speakers learning Chinese: Using 会 for all ability: 我会吃十个包子 → 我能吃十个包子 (physical capacity needs 能)
-
Chinese speakers learning English: Using ‘will’ for everything: I will can → I will be able to
Related topics
- Verb Tenses: How modals interact with tense in Spanish and English
- Questions: How modal verbs form questions without ‘do’ support
- Negation: How modal negation works differently across languages
- Word Order: How Chinese auxiliaries position before the main verb
Examples
Ability (can)
puedo / sé
Possibility (may/might)
puede que + subjuntivo
Permission (may)
puedes
Obligation (must/have to)
debo / tengo que
Prohibition (must not)
no debes / no puedes
Future intention (will)
voy a / hablaré
Advice (should)
deberías
Form changes with person/tense
Yes (conjugated)
Examples
Ability (can)
can / could
Possibility (may/might)
may / might
Permission (may)
may / can
Obligation (must/have to)
must / have to / should
Prohibition (must not)
must not / cannot
Future intention (will)
will / shall
Advice (should)
should / ought to
Form changes with person/tense
No (modals invariable)
Examples
Ability (can)
能 / 会
Possibility (may/might)
可能
Permission (may)
可以
Obligation (must/have to)
必须 / 应该 / 要
Prohibition (must not)
不能 / 不可以
Future intention (will)
要 / 会
Advice (should)
应该
Form changes with person/tense
No (auxiliaries invariable)
Comparison at a glance
| Grammar concepts | Spanish | English | Chinese |
|---|---|---|---|
| Ability (can) | puedo / sé | can / could | 能 / 会 |
| Possibility (may/might) | puede que + subjuntivo | may / might | 可能 |
| Permission (may) | puedes | may / can | 可以 |
| Obligation (must/have to) | debo / tengo que | must / have to / should | 必须 / 应该 / 要 |
| Prohibition (must not) | no debes / no puedes | must not / cannot | 不能 / 不可以 |
| Future intention (will) | voy a / hablaré | will / shall | 要 / 会 |
| Advice (should) | deberías | should / ought to | 应该 |
| Form changes with person/tense | Yes (conjugated) | No (modals invariable) | No (auxiliaries invariable) |
Select at least one language to view comparisons
Side-by-side comparison
| Grammar concepts | Spanish | English | Chinese |
|---|---|---|---|
| Ability (can) | puedo / sé | can / could | 能 / 会 |
| Possibility (may/might) | puede que + subjuntivo | may / might | 可能 |
| Permission (may) | puedes | may / can | 可以 |
| Obligation (must/have to) | debo / tengo que | must / have to / should | 必须 / 应该 / 要 |
| Prohibition (must not) | no debes / no puedes | must not / cannot | 不能 / 不可以 |
| Future intention (will) | voy a / hablaré | will / shall | 要 / 会 |
| Advice (should) | deberías | should / ought to | 应该 |
| Form changes with person/tense | Yes (conjugated) | No (modals invariable) | No (auxiliaries invariable) |
Select at least one language to view comparisons
Examples in context
Ability (can)
Spanish
puedo / sé
English
can / could
Chinese
能 / 会
Possibility (may/might)
Spanish
puede que + subjuntivo
English
may / might
Chinese
可能
Permission (may)
Spanish
puedes
English
may / can
Chinese
可以
Obligation (must/have to)
Spanish
debo / tengo que
English
must / have to / should
Chinese
必须 / 应该 / 要
Prohibition (must not)
Spanish
no debes / no puedes
English
must not / cannot
Chinese
不能 / 不可以
Future intention (will)
Spanish
voy a / hablaré
English
will / shall
Chinese
要 / 会
Advice (should)
Spanish
deberías
English
should / ought to
Chinese
应该
Form changes with person/tense
Spanish
Yes (conjugated)
English
No (modals invariable)
Chinese
No (auxiliaries invariable)
Select at least one language to view comparisons
Key Takeaways
Spanish: Uses conjugated verbs (poder, deber, querer) that inflect for person and tense. The subjunctive is required for many modal expressions.
English: Uses a small, closed set of invariable modals (can, could, may, might, must, shall, should, will, would). They never change form.
Chinese: Uses auxiliary verbs (会, 能, 可以, 要, 应该) placed before the main verb. They do not conjugate.
Key concepts compared: Ability (can), Possibility (may/might), Permission (may).
Frequently Asked Questions
Why does English have only 9 modal verbs while Spanish uses full verb conjugation?
How do Spanish and Chinese distinguish between physical ability and learned skill?
Why is 'It may rain' translated with the subjunctive in Spanish?
References
- Nueva gramática de la lengua española — Real Academia Española / Asociación de Academias de la Lengua Española, 2010
- The Cambridge Grammar of the English Language — Huddleston & Pullum, Cambridge University Press, 2002
- A Comprehensive Grammar of the Modern Chinese Language — Li & Thompson, 1981
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Last updated: June 4, 2026