Grammar Glow

What is "Can"?

"Can" is a modal verb used to express different abilities, permissions, possibilities, and requests.

Characteristics of "Can"

1. Expressing Ability:

"Can" is most commonly used to show that someone is able to do something, or that something is possible.

Examples

I can swim. (This shows the ability to swim.)

2. Making Requests:

"Can" is used to ask someone to do something or for permission in an informal way.

Examples

Can you pass me the salt? (This is a request for action.)

3. Giving or Asking for Permission:

"Can" can also be used to give or ask for permission in informal contexts.

Examples

You can go now. (Permission is granted.)
Can I borrow your pen? (Asking for permission.)

4. Expressing Possibility:

"Can" is used to state that something is possible or likely.

Examples

It can get very hot here in the summer. (Shows that it is possible for this to happen.)

How "Can" is Used in Sentences

1. Affirmative Sentence Structure:

Structure:

Subject + "can" + base verb.

Examples

She can speak three languages.

2. Negative Sentence Structure:

Structure:

Subject + "cannot" or "can't" + base verb.

Examples

They can't come to the party tomorrow.

3. Question Sentence Structure:

Structure:

"Can" + subject + base verb?

Examples

Can you help me with my homework?

What is "Could"?

"Could" is a modal verb, often considered the past form of "can," though it has several uses beyond just indicating past ability. It is used to express possibilities, polite requests, past abilities, and suggestions.

Characteristics of "Could"

1. Expressing Past Ability:

"Could" is used to indicate that someone had the ability to do something in the past.

Examples

When I was younger, I could run fast.

2. Making Polite Requests:

"Could" is commonly used to make polite or formal requests.

Examples

Could you please open the window?

3. Asking for or Giving Permission (Politely):

"Could" is used for polite requests for permission, especially in formal contexts.

Examples

Could I leave early today?
You could go if you like.

4. xpressing Possibility or Suggestion:

"Could" is used to talk about something that is possible or to suggest options.

Examples

It could rain later.
You could try restarting the computer.

5. Expressing Uncertainty or Hypothetical Situations:

"Could" is used to express uncertainty or hypothetical possibilities.

Examples

He could be at the office, but I’m not sure.

How "Could" is Used in Sentences

1. Affirmative Sentence Structure:

Structure:

Subject + "could" + base verb.

Examples

She could play the piano when she was five.

2. Negative Sentence Structure:

Structure:

Subject + "could not" or "couldn’t" + base verb.

Examples

They couldn’t understand the instructions.

3. Question Sentence Structure:

Structure:

"Could" + subject + base verb?

Examples

Could you help me with my project?

Differences Between Can and Could

1. Present vs. Past Ability:

A - Can is used to express abilities or possibilities in the present or future.

Example: I can swim.

B - Could is often used to express abilities in the past.

Example: I could swim when I was a child.

2. Politeness Levels in Requests:

A- Can is used for informal requests or when asking permission. It is generally more direct.

Example: Can you help me with my homework?

B - Could is used for more polite or formal requests.

Example: Could you please help me with my homework?

What is "Can"?Characteristics of "Can"How "Can" is Used in Sentences What is "Could"?Characteristics of "Could"How "Could" is Used in Sentences Differences Between Can and Could