Modal & Auxiliary Verbs Complete Guide: Can/Could, May/Might, Must/Have To, Should/Ought To

Modal & Auxiliary Verbs Complete Guide

English Grammar • Modal & Helping Verbs • Urdu Examples • Updated December 2025 • Practice Exercises Included

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Modal verbs and auxiliary verbs are the "helping verbs" that give English its precision and nuance. This guide covers all modal verbs (can, could, may, might, must, should, would, will) and auxiliary verbs (do, does, did, has, have, had) with rules, differences, and Urdu examples.

Modal verbs are special verbs that modify the main verb to express ability, possibility, permission, obligation, or advice.

✅ Key Characteristics of Modal Verbs:
  1. No -s in third person: He can speak (not cans)
  2. No infinitive form: We don't say "to can" or "to must"
  3. No -ing form: No "musting" or "canning"
  4. Followed by base verb: Can speak, must go
  5. Questions/Negatives without "do": Can I? Must I not?
Modal Verb Primary Use Strength Level Urdu Meaning Example
Can Ability, Permission Medium سکتا ہے، کر سکتا ہے I can swim.
Could Past ability, Polite request Medium سکتا تھا، کر سکتا تھا Could you help?
May Permission, Possibility Formal/Medium سکتا ہے (اجازت)، ہو سکتا ہے May I come in?
Might Weak possibility Weak شاید، ہو سکتا ہے It might rain.
Must Strong obligation Strong ضرور، لازمی ہے You must study.
Should Advice, Recommendation Medium چاہیے، کرنا چاہیے You should rest.
Ought to Moral obligation Formal/Strong چاہیے (اخلاقی ذمہ داری) You ought to help.
Will Future, Determination Strong گا، گی، گے I will come.
Would Conditional, Polite request Medium کرتا، ہوتا (شرطیہ) Would you like tea?

🔷 Can vs Could – Rules and Detailed Examples

Can and Could are among the most frequently used modal verbs.

CAN (Present Ability/Permission)

Uses:

  • Present ability
  • Informal permission
  • General possibility
  • Requests (informal)

حال کی صلاحیت، غیر رسمی اجازت

COULD (Past/Polite)

Uses:

  • Past ability
  • Polite requests
  • Conditional
  • Suggestions

ماضی کی صلاحیت، شائستہ درخواست

Usage CAN Examples COULD Examples Difference
Ability I can swim. (present) I could swim when I was 5. (past) Time difference
Permission Can I go? (informal) Could I go? (polite) Formality level
Possibility It can be dangerous. (general) It could rain. (specific) General vs specific
Request Can you help? (casual) Could you help? (polite) Politeness level
⚠️ Important Rule: Did کے ساتھ verb کی پہلی شکل استعمال ہوتی ہے، دوسری شکل نہیں۔
❌ Did she went to school?
✅ Did she go to school?

🔷 May vs Might – Complete Difference with Examples

May and Might express possibility, but with different degrees of certainty.

Might (Weak)
Could (Medium)
May (Stronger)
Aspect MAY MIGHT Key Difference
Possibility 50-70% likely 30-50% likely Degree of certainty
Permission Formal permission Not used for permission May only for permission
Formality More formal Less formal Context matters
Past Form Might (as past of may) Might (no change) Same in past tense

Possibility Examples:

  • May: She may come to the party. (more likely)
  • Might: She might come to the party. (less likely)

Permission Examples:

  • May: May I use your phone? (formal permission)
  • May not: You may not leave early. (formal prohibition)
  • ❌ Incorrect: Might I use your phone? (not used for permission)

🔷 Must vs Have To – Easy Explanation

Both express obligation, but the source of obligation is different.

MUST (Internal Obligation)

Source: Speaker's opinion/rules

Strength: Very strong

Examples:

  • I must study. (I feel I need to)
  • You must obey. (my rule)

ذاتی ذمہ داری، اپنا فیصلہ

HAVE TO (External Obligation)

Source: External rules/laws

Strength: Strong

Examples:

  • I have to work. (boss requires)
  • You have to pay tax. (law)

بیرونی ذمہ داری، قوانین

Situation MUST HAVE TO Reason
Personal opinion You must see this movie! ❌ Not used Must = personal feeling
Rules/laws ❌ Not usually You have to wear a seatbelt. Have to = external rule
Logical conclusion He must be tired. (deduction) ❌ Not used Must for deduction
Past obligation ❌ No past form I had to work yesterday. Have to has past form
⚠️ CRITICAL DIFFERENCE:
Must not = prohibition (منع ہے)
Don't have to = no obligation (ضرورت نہیں)
Example: You must not smoke here. (prohibited)
Example: You don't have to come. (optional)

🔷 Should vs Ought To – Detailed Comparison

Both give advice or make recommendations, but with different connotations.

Feature SHOULD OUGHT TO Notes
Frequency Very common Less common Should is more frequent
Formality Neutral More formal Ought to sounds formal
Strength Medium advice Stronger moral duty Ought to = moral obligation
Negatives Shouldn't Ought not to (rare) Shouldn't is common
Questions Should I...? Ought I to...? (rare) Should questions are common

For Advice (Both acceptable):

  • You should see a doctor.
  • You ought to see a doctor. (slightly stronger)

For Moral Obligation (Ought to preferred):

  • We ought to help the poor. (moral duty)
  • You ought to respect your elders.

🔷 Would vs Will – Complete Usage Guide

Will is for definite future, while Would is for hypothetical or polite situations.

WILL (Definite Future)

Primary Uses:

  • Future tense
  • Promises
  • Instant decisions
  • Predictions

Example: I will call you tomorrow.

WOULD (Hypothetical/Polite)

Primary Uses:

  • Conditional sentences
  • Polite requests
  • Past habits
  • Preferences

Example: I would help if I could.

Situation WILL Example WOULD Example Explanation
Future action I will meet you at 5. ❌ Not used Will for definite future
Conditional ❌ Not used I would go if I had time. Would in conditionals
Polite request Will you pass the salt? Would you pass the salt? Would is more polite
Past habits ❌ Not used When I was young, I would play cricket. Would for past habits
Preferences ❌ Not used I would rather stay home. Would for preferences

🔄 Auxiliary Verbs (Do, Does, Did, Has, Have, Had)

Auxiliary Verbs (Do, Does, Did)

Auxiliary Use With Subject Example Sentences
Do Present simple (I/you/we/they) Plural subjects, I, you Do you like tea? I do not know.
Does Present simple (he/she/it) Singular third person Does she work here? He does not agree.
Did Past simple (all subjects) All subjects in past Did they come? We did not see him.

Uses of Has, Have, Had

Verb Subject As Main Verb As Auxiliary Verb
Have I, You, We, They I have a car. (possession) I have finished. (present perfect)
Has He, She, It She has a book. (possession) She has gone. (present perfect)
Had All subjects (past) I had a bike. (past possession) I had finished. (past perfect)

Common Mistakes and Corrections:

  • ❌ Incorrect: I has a book. → ✅ Correct: I have a book.
  • ❌ Incorrect: She have gone. → ✅ Correct: She has gone.
  • ❌ Incorrect: They has been waiting. → ✅ Correct: They have been waiting.

📝 Comprehensive Practice Exercises

Exercise 1: Choose Correct Modal Verb
  1. You ______ see a doctor about that cough.
    Answer: should / ought to (advice)
  2. ______ I use your phone? (polite request)
    Answer: Could / May
  3. She ______ speak three languages. (ability)
    Answer: can
  4. It ______ rain later. (possibility)
    Answer: might / may / could
  5. I ______ wear a uniform at school. (obligation from rules)
    Answer: have to
Exercise 2: Correct the Mistakes
  1. She can to speak French. → She can speak French.
  2. Does he works here? → Does he work here?
  3. I must to finish this today. → I must finish this today.
  4. They has been waiting for hours. → They have been waiting for hours.
Exercise 3: Translate to English
  1. کیا میں آپ کا قلم استعمال کر سکتا ہوں؟
    Answer: May/Could I use your pen?
  2. آپ کو ڈاکٹر کے پاس جانا چاہیے۔
    Answer: You should see a doctor.
  3. مجھے کل کام پر جانا ہوگا۔
    Answer: I have to go to work tomorrow.

Quick Reference Table

Verb Primary Use Key Rule Example
Can Ability, Permission Present ability, informal permission I can swim.
Could Past ability, Polite requests More polite than can Could you help?
May Formal permission, Possibility Formal situations May I come in?
Might Weak possibility Less certain than may It might rain.
Must Strong obligation (internal) Speaker's opinion You must try this.
Have to Obligation (external) Rules/laws require I have to work.
Should Advice, Recommendation Common, neutral You should rest.
Will Future, Promises Definite future I will call.
Would Conditional, Polite Hypothetical situations I would if I could.

مدل افعال اور معاون افعال انگریزی کے اہم ستون ہیں۔ ان کو سمجھنا اور صحیح استعمال کرنا فصیح انگریزی بولنے کے لیے ضروری ہے۔

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