Difference WikiGrammar

Difference Between Can and Could

Main Difference

The main difference between Can and Could is that ‘Can’ is used to express the ability of a person to do something in the present, whereas ‘Could’ express the ability of a person to do something in the past.

Can vs. Could

The word ‘Can’ is another form of the word ‘Could.’ ‘Could’ is also known to be a form of the word ‘Can.’ ‘Can’ is used to express the ability of a person to do something in the present. ‘Could’ express the ability of a person to do something in the past. ‘Can’ is a present ability. ‘Could’ is a past ability. ‘Can’ gives the meaning of ‘to be able to do something.’ It can also replace with ‘be able to’ in some cases. For example, if a person says that he can sing, it means that he can sing. But if we replace this ‘Can’ with its counterpart ‘Could,’ then the sentence will convey a different meaning. ‘I could sing’ means that the person was able to sing earlier, but now he cannot for some reason, i.e., he lost his voice.

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‘Can’ is used to make comprehensive affirmations to show the possibility, e.g., It can be very hot here in summer. This sentence is conveying that the chances of the hottest summer are frequent in that area. ‘Could’ is used to show when something is possible but not sure, e.g., They could go to the market. This sentence is reflecting a vague idea that maybe they will go to the market or maybe not. Hence, ‘Can’ convey a specific idea while ‘Could’ convey a vague idea.

‘Can’ sound less polite, and it is used in a less formal situation, while if a person is in a more formal situation, he/she uses ‘Could’ to make offers, requests, or to give suggestions. ‘Can’ is pronounced as kan/kən. ‘Could’ is pronounced as kəd/kʊd.

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Comparison Chart

CanCould
Express the ability of a person to do something in the presentExpress the ability of a person to do something in the past
Pronunciation
kan/kənkəd/kʊd
Conveys
Certain ideaVague idea
Use
Less formalMore formal
Sounds
Less politeMore polite
Possibility
PresentPast
Letters
ThreeFive

What is Can?

‘Can’ is used to ask for permission, e.g., Can I take your pencil? In the same way, it also used yo grant permission like “You can take my pencil.” In the context of authority, ‘Can’ refers that someone who has permission to do something, e.g., You can hang out with my friends. There is always a negative statement with ‘Can’ where there is a positive statement. So ‘Can’ also refer to if someone does not have permission to do something, e.g., You can not hang out with your friends.

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‘Can’ is used to express the ability of a person to do something in the present. ‘Can’ gives the meaning of ‘to be able to do something.’ It can also replace with ‘be able to’ in some cases. ‘Can’ is used to make general statements to show the possibility.

‘Can’ sound less polite, and it used in a less formal situation, and it pronounced as kan/kən. ‘Can’ also express some possibility, e.g., The intake of alcohol can damage your lungs. There are some other meanings of the word ‘Can’ too. ‘Can’ is a sort of small cylindrical shaped container usually made of metal. The word ‘Can’ is also a verb (auxiliary verb) meaning to stop something, to put something in a container, or to fire someone from a job.

Examples

  • I can do it alone.
  • You can do it!
  • Smoking can damage your lungs.
  • You can achieve your dream if you work hard.

What is Could?

‘Could’ is a modal verb. It is the past participle form of the verb that used with the main verb. ‘Could’ express the ability of a person to do something in the past. ‘I could sing’ means that the person was able to sing earlier, but now he cannot for some reason, i.e., he lost his voice. ‘Could’ is used to show when something is possible but not sure.

‘Could’ is used in a more formal situation. It is more precise than its counterpart ‘Can.’ For instance, Could I go home, please? ‘Could’ is pronounced as kəd/kʊd. The phrase could you is used as a polite way of asking someone to do something, e.g., Could I have my file back? ‘Could’ also make an offer like I could do your homework. We use ‘Could’ to make a request, e.g., Could you tell me it’s the recipe? It gives the meaning of suggestion or advice, e.g. You could go to London for higher studies.

Furthermore, ‘Coul’d is used when someone is imagining or fantasizing a thing, e.g., I wish I could meet a real mermaid. ‘Could’ is used in conditional sentences as ‘the doctors could save him if they have brought him to the hospital on time.’ Could express possibility from the past, e.g., You could have done it on time if you have tried.

Examples

  • Could I use your pen?
  • He could not go to the party because he is sick.
  • We could watch a movie if you want to.
  • I asked you to walk slowly. You could have slipped.

Key Differences

  1. ‘Can’ is used to express the ability of a person to do something in the present, whereas ‘Could’ express the ability of a person to do something in the past.
  2. ‘Can’ have less formal use; on the other hand, ‘Could’ have a more formal use.
  3. ‘Can’ is a present ability; conversely, ‘Could’ is a past ability.
  4. ‘Can’ is pronounced as kan/kən, contrarily ‘Could’ is pronounced as kəd/kʊ.
  5. ‘Can’ convey a less polite meaning; on the contrary, ‘Could’ give a more polite meaning.
  6. ‘Can’ gives the meaning of ‘to be able to do something,’ on the other side ‘Could’ give the meaning of ‘was able to do something.’
  7. ‘Can’ is used to make general statements to show the possibility, on the converse ‘Could’ is used to show when something is possible but not certain.
  8. ‘Can’ convey a specific idea, inversely ‘Could’ convey a vague idea.

Conclusion

Can and Could are the two modal verbs with a different context. Their difference lies in their usage. Can and Could express distinct moods.

Aimie Carlson

Aimie Carlson is an English language enthusiast who loves writing and has a master degree in English literature. Follow her on Twitter at @AimieCarlson