Exercise 1
Choose the correct form of can or cannot to complete each sentence.
Example: She ___ speak English. (can / cannot)
Answer: She can speak English.
Modal Verbs: CAN
In this lesson, we learn about the modal verb can. We use can to talk about ability — things we are able to do. We also use can to ask for permission or to offer help.
Look at these simple examples:
- I can swim. (I am able to swim.)
- She can speak English. (She is able to speak English.)
- Can you help me? (Is it possible for you to help me?)
Can is a very common and useful word in English. Let's learn how to use it step by step.
What Is a Modal Verb?
A modal verb is a special helping verb. It goes before the main verb in a sentence. It changes the meaning of the main verb.
Can is a modal verb. It tells us that something is possible or that someone is able to do something.
Here is a simple example:
- I swim. → This is a simple fact.
- I can swim. → This means I have the ability to swim.
The word can adds extra meaning to the main verb.
Rule Breakdown: Positive Sentences with CAN
To make a positive sentence with can, use this pattern:
Subject + can + main verb (base form)
The subject is the person or thing doing the action. For example: I, you, he, she, it, we, they.
The base form of the verb is the simple, dictionary form. For example: swim, run, speak, cook, read, sing.
Look at these examples:
- I can run fast.
- You can cook dinner.
- He can play football.
- She can sing well.
- It can fly. (for example, a bird)
- We can speak French.
- They can read English.
Notice something very important: can does not change. It is the same for every subject — I, you, he, she, it, we, they. We never say he cans or she cans.
Positive Sentences with CAN: Table
| Subject | Can | Main Verb | Example Sentence |
|---|---|---|---|
| I | can | swim | I can swim. |
| You | can | drive | You can drive a car. |
| He | can | play | He can play the guitar. |
| She | can | cook | She can cook pasta. |
| It | can | run | It can run fast. (a dog) |
| We | can | dance | We can dance. |
| They | can | speak | They can speak Spanish. |
Rule Breakdown: Negative Sentences with CAN
To make a negative sentence with can, add not after can:
Subject + cannot + main verb (base form)
We write cannot as one word. This is the full negative form.
Look at these examples:
- I cannot swim.
- He cannot drive.
- She cannot speak German.
- We cannot come to the party.
- They cannot play tennis.
The Short Form: Can't
In everyday spoken English, we often use the short form (called a contraction). A contraction is when we join two words together and use an apostrophe (') in place of the missing letters.
cannot → can't
The apostrophe (') replaces the letters no.
- I can't swim.
- He can't drive.
- She can't speak German.
- We can't come to the party.
- They can't play tennis.
Cannot and can't have the same meaning. Can't is more common in speaking. Cannot is more common in writing.
Negative Sentences with CAN: Table
| Subject | Cannot / Can't | Main Verb | Example Sentence |
|---|---|---|---|
| I | cannot / can't | swim | I cannot swim. / I can't swim. |
| You | cannot / can't | drive | You cannot drive. / You can't drive. |
| He | cannot / can't | play | He cannot play. / He can't play. |
| She | cannot / can't | cook | She cannot cook. / She can't cook. |
| It | cannot / can't | fly | It cannot fly. / It can't fly. |
| We | cannot / can't | dance | We cannot dance. / We can't dance. |
| They | cannot / can't | speak | They cannot speak. / They can't speak. |
Rule Breakdown: Questions with CAN
To make a question with can, put can at the beginning of the sentence, before the subject:
Can + subject + main verb (base form)?
Look at these examples:
- Can you swim?
- Can he play football?
- Can she sing?
- Can they speak English?
- Can we sit here?
To answer a yes/no question with can, use a short answer:
Yes, + subject + can.
No, + subject + cannot. / No, + subject + can't.
- Can you swim? → Yes, I can. / No, I can't.
- Can he play football? → Yes, he can. / No, he can't.
- Can they speak French? → Yes, they can. / No, they can't.
Important: In short answers, we always use can or can't. We do not use cannot in short answers.
Questions with CAN: Table
| Question | Positive Answer | Negative Answer |
|---|---|---|
| Can I help you? | Yes, you can. | No, you can't. |
| Can you cook? | Yes, I can. | No, I can't. |
| Can he run fast? | Yes, he can. | No, he can't. |
| Can she dance? | Yes, she can. | No, she can't. |
| Can it swim? | Yes, it can. | No, it can't. |
| Can we go now? | Yes, we can. | No, we can't. |
| Can they play tennis? | Yes, they can. | No, they can't. |
Three Ways to Use CAN
We use the modal verb can in three main situations at this level:
1. Ability
We use can to say that someone is able to do something.
- I can ride a bike. (I know how to do it.)
- My sister can speak three languages.
- Our dog can catch a ball.
2. Permission
We use can to ask for permission (to ask if something is allowed) or to give permission.
- Can I open the window? (Is it OK if I open it?)
- Yes, you can. (Yes, it is allowed.)
- You can sit here. (It is OK to sit here.)
3. Requests
We use can to ask someone to do something.
- Can you help me, please?
- Can you open the door?
- Can you say that again, please?
A Mini Story: Meet Tom and Sara
Read this short story. Look at how we use can and can't.
Tom and Sara are friends. Tom can swim very well, but he can't cook. Sara can cook delicious food, but she can't swim.
One day, Sara asks: "Can you teach me to swim, Tom?"
Tom says: "Yes, I can! Can you teach me to cook?"
Sara smiles: "Yes, I can!"
In this story, we can see can used for ability (Tom can swim, Sara can cook) and for requests (Can you teach me?).
Important Differences and Special Cases
CAN vs. Cannot / Can't
Remember: cannot is one word. Do not write it as two words (can not) unless you want to give extra strong emphasis. In normal sentences, always write cannot as one word.
- ✅ I cannot swim. (correct — one word)
- ✅ I can't swim. (correct — contraction)
- ❌ I can not swim. (not standard in normal sentences)
CAN and the Main Verb
After can, always use the base form of the verb. The base form is the simple form with no endings like -s, -ing, or -ed.
- ✅ She can sing. (base form: sing)
- ❌ She can sings. (do not add -s)
- ❌ She can singing. (do not add -ing)
- ❌ She can singed. (do not add -ed)
CAN Does Not Change
The word can is the same for all subjects. It does not change its form.
- ✅ He can play.
- ❌ He cans play. (never add -s to can)
Common Mistakes
Here are some common mistakes students make with the modal verb can. Study these carefully!
❌ She cans swim.
✅ She can swim. (can never has an -s)
❌ He can swims.
✅ He can swim. (the main verb stays in base form)
❌ I can not speak French.
✅ I cannot speak French. (cannot is one word)
❌ Can you to help me?
✅ Can you help me? (do not use "to" after can)
❌ She can to dance.
✅ She can dance. (do not use "to" after can)
❌ Can he plays guitar?
✅ Can he play guitar? (use base form in questions too)
❌ Yes, I can swim. (in a short answer)
✅ Yes, I can. (short answers do not repeat the main verb)
CAN: Full Sentence Patterns at a Glance
| Sentence Type | Pattern | Example |
|---|---|---|
| Positive | Subject + can + base verb | I can swim. |
| Negative (full) | Subject + cannot + base verb | I cannot swim. |
| Negative (short) | Subject + can't + base verb | I can't swim. |
| Question | Can + subject + base verb? | Can you swim? |
| Short answer (yes) | Yes, + subject + can. | Yes, I can. |
| Short answer (no) | No, + subject + can't. | No, I can't. |
Modal Verbs: CAN — Quick Summary
Let's look at the key points from this lesson:
- Can is a modal verb. It goes before the main verb.
- We use can to talk about ability (things we know how to do), permission (asking if something is allowed), and requests (asking someone to do something).
- Can is the same for all subjects: I, you, he, she, it, we, they. We never say cans.
- After can, always use the base form of the verb. Never add -s, -ing, or -ed. Never add to.
- The negative form is cannot (one word) or the contraction can't.
- To make a question, put can at the beginning: Can you help me?
- Short answers use can or can't only: Yes, I can. / No, I can't.
Now practise modal verbs: can in the exercises below.
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