In this lesson you will understand what modal verbs are, how to use them, what they are for and which real situations they fit 📖. You will learn to tell apart modals of obligation, possibility, permission and advice 🧠, with real practice in the quiz at the bottom of the page! 🚀
🧠 What are modal verbs?
Modal verbs are special auxiliary verbs that change the meaning of the main verb. They follow three basic rules:
They never change form: no “-s” for he/she/it, no “-ed” in the past, no “-ing”.
They are followed by the base verb (without TO): put the base form of the verb straight after them (exceptions: ought to, have to).
They do not use DO/DOES/DID in questions or negatives: they make questions and negatives by themselves (e.g. Can you? / I cannot).
❌ He can to swim ➔ ✅ He can swim 🏊
🧩 Table of all the main modal verbs
Modal
Main use
Example
In a picture
Can
Ability / Possibility
I can swim.
🏊♂️
Could
Past ability / Possibility
I could run fast.
🏃
May
Formal permission / Possibility
May I come in?
🚪
Might
Remote possibility
It might rain.
🌧️
Must
Strong obligation / Deduction
You must study.
📚
Shall
Offer / Suggestion (UK)
Shall we go?
🤝
Should
Advice
You should sleep.
😴
Will
Future / Willingness
I will call you.
📞
Would
Hypothesis / Politeness
Would you help me?
🙏
Ought to
Formal advice
You ought to stop.
🛑
Need (modal)
Necessity
Need I wait?
⏳
📘 1. Modals of ability
Modal
Tense
Example
Meaning
Can
Present
She can dance. 💃
Ability now 💃
Could
Past / Hypothesis
He could swim at 5. 🧒
Ability in the past 🏊
Be able to
All tenses (alternative)
I will be able to go. 🚗
Ability in the future
📘 2. Modals of permission and possibility
Modal
Level of formality / Probability
Example
Uso
Can
Informal
Can I leave early?
Practical / informal permission
May
Formal (50-70% probability)
May I help you? / It may rain.
Polite permission / Medium possibility
Might
Uncertain (20-40% probability)
He might come later.
Remote possibility
📘 3. Modals of obligation
Modal / Structure
Type of obligation
Example
Meaning in simple words
Must
Internal / Personal rule / Strong moral duty
I must work. 💼
I really have to (my own decision).
Have to
External / Law / Imposed rule
I have to pay taxes. 💰
I have to (a law or rule says so).
Need to
Practical need
I need to sleep. 😴
I need to sleep.
📘 4. Modals of advice
Modal
Strength
Example
Meaning in simple words
Should
Standard advice
You should eat better. 🥗
Good advice: eat better. 🥗
Ought to
Formal / moral advice
You ought to rest. 🛌
Stronger advice: you really should rest. 😴
Shall
Proposal / Suggestion (UK)
Shall we dance? 💃
A suggestion or an offer: let’s dance? 💃
📘 5. Modals of future, hypothesis and politeness
Modal
Uso
Example
Meaning
Will
Sure future / Instant decision
I will help you. ✅
A promise to help. 🤝
Would
Conditional / Polite request
Would you like coffee? ☕
A polite offer. ☕
📌 Comparison table – All modals
Modal
Ability
Permission
Possibility
Obligation
Advice
Future / Hypothesis
Can
✅
✅
✅
❌
❌
❌
Could
✅ (past)
✅
✅ (remote)
❌
❌
✅ (hypothesis)
May
❌
✅ (formal)
✅
❌
❌
❌
Might
❌
❌
✅ (remote)
❌
❌
✅
Must
❌
❌
❌
✅
❌
❌
Should
❌
❌
❌
❌
✅
❌
Will
❌
❌
❌
❌
❌
✅
Would
❌
❌
❌
❌
❌
✅ (conditional)
🚫 Common mistakes
Mistake ❌
Correct ✅
Explanation
He can to speak
He can speak
No “to” after a modal verb!
I must to go
I must go
No “to” after “must”.
Can I to go to the bathroom?
Can I go to the bathroom?
No “to” after the modal in questions.
I will can go
I will be able to go
“Can” has no future form: use “be able to”!
You mustn’t to smoke
You mustn’t smoke
Negative form ➔ no “to”.
Do you can swim?
Can you swim?
Modals make questions by themselves (no do/does).
📌 Final summary
✔ Modal verbs stay the same with every subject (no -s).
✔ They go straight before the base form of the verb (no to).
✔ They do not use do/does/did to make questions or negatives.
✔ For missing tenses (e.g. the future of can or must), use be able to and have to!
Modal verbs are essential for expressing intention, probability and politeness in English! ✨
Gap Fill & Translation Exercises
Test yourself! In the first 15 sentences, fill the gap with the modal verb or the correct form. In the last 5, build the English sentence from the words given.
