Can vs Could | Difference, Definitions & Examples
Can and could both convey ability and possibility. “Can” expresses that something is known to be true or highly likely to happen (e.g., “Scorching hot coffee can burn you”), while “could” refers to something that is less certain but still possible (e.g., “I could probably make the team”).
“Can” and “could” are also used when asking for something or seeking permission. When used for these purposes, “could” is considered more formal and courteous (e.g., “Could you hand that to me, please?”). Additionally, “could” is often used to provide suggestions (e.g., “You could come in later in the morning if you’re too tired”).
| Examples: Can in a sentence | Examples: Could in a sentence |
|---|---|
| Clothes can get damaged in the dryer if the temperature is too high. | You could probably make it on time if you take North Avenue to avoid the traffic. |
| I love books and can read up to five of them every month. | It was only after she left that I learned she could have fixed my laptop for me. |
| My grandma is arriving from France today, so can I go home early to greet her? | Could you edit the last paragraph and make it more memorable? |
What’s the difference between can and could?
“Can” and “could” are modal verbs that provide further information about the main verb. “Can” is the present tense form of the verb, while “could” is the past tense form. Both words indicate the ability or possibility for something to happen.
However, when expressing possibility, both words can function in the future tense, which is a major source of confusion. But there are a few key differences between “can” and “could” that help clarify their correct usage.
Can or could to express ability
When indicating the ability to do something, “can” is used in the present tense, while “could” is used in the past tense.
Past tense: When I was younger, I could bench press eighty pounds.
Present tense: My car can take me from Miami to Orlando on one tank of gas.
Past tense: Back then, my car could take me from Miami to Orlando on one tank of gas.
Can or could to express possibility
When expressing possibility, “can” is used to state a general fact or express that something is very likely to happen, whereas “could” conveys that something is possible but not as certain to happen.
Less certain but possible: It could rain tomorrow, but I’m not sure.
General truth/highly likely: You can get sick if your vitamin D levels are low.
Less certain but possible: You could improve your immune system if you supplement vitamin D.
Additionally, “could” is used in the subjunctive mood to describe a hypothetical situation in the past, present, or future tense. In the past subjunctive mood, “could” is usually followed by “have.”
Present: Things could be going better if our instructions were clearer.
Future: If they were to come on time, I could go through the entire presentation.
Can or could to ask or give permission
When it comes to permission, “can” is more casual and informal and is used to ask for and give permission. However, “could” is considered more formal and respectful and is typically used to ask for permission but not to grant it.
Formal/polite: Could I go have dinner with my friends tonight?
Giving permission: Yes, you can go to dinner with your friends tonight.
Casual/informal: Can Elizabeth provide her input on the project?
Formal/polite: Could Elizabeth provide her input on the project?
Giving permission: Yes, Elizabeth can provide her input on the project.
Can or could to make requests or suggestions
When making requests, you can use “can” and “could” interchangeably, but “can” is considered more casual, whereas “could” is more formal and polite.
Formal and polite: Could you lower the music a bit?
Casual and informal: Can you help bring in the furniture?
Formal and polite: Could you help bring in the furniture?
“Could” is often used when making suggestions. Using “can” in place of “could” when suggesting something can be mistakenly interpreted as giving permission.
You can go home early if you’re not feeling well. (Implies permission)
Frequently asked questions about can vs could
- What is a synonym of could?
-
A few synonyms of the verb “could” when referring to ability or possibility include:
- Managed to
- Had the ability to
- Was able to
- Was capable of
A few synonyms of “could” when referring to past permission include:
- Had permission to
- Was allowed to
Try QuillBot’s rewriter to find synonyms for words like “could.”
