Investigation
About use can and could
Name: Andrea Carrión ID: 2-755-2218
Investigation of the Use of "Can" and "Could"
The modal verbs "can" and "could" are widely used in English, each serving multiple
functions and conveying different nuances. This investigation examines their uses and
differences, with examples to illustrate each point.
1. Basic Functions of "Can"
"Can" is used to express the following:
Ability: Describes someone's capability or skill.
o Example: "She can swim." (She has the ability to swim.)
Possibility: Indicates that something is possible.
o Example: "You can catch the bus from the station." (It is possible to catch
the bus there.)
Permission: Used to ask for or grant permission.
o Example: "Can I borrow your pen?" (Asking for permission to borrow a
pen.)
Request: Often used to make informal requests.
o Example: "Can you help me with this?" (Requesting help.)
Offer: Used to offer help or service.
o Example: "Can I get you something to drink?" (Offering a drink.)
2. Basic Functions of "Could"
"Could" serves as the past tense of "can" but is also used to express:
Past Ability: Indicates someone was able to do something in the past.
o Example: "She could swim when she was five." (She had the ability to swim
in the past.)
Polite Requests: More polite than "can" when making requests.
o Example: "Could you pass the salt?" (Requesting salt politely.)
Suggestions: Used to propose options or alternatives.
o Example: "You could try restarting your computer." (Suggesting restarting
as a solution.)
Possibility: Describes something that is possible but not certain.
o Example: "It could rain tomorrow." (There's a possibility of rain.)
Conditional Ability: Used in hypothetical or conditional statements.
o Example: "If I had time, I could help you." (Ability contingent on having
time.)
3. Comparison of "Can" and "Could"
1. Requests and Offers
"Can" is used for direct and informal requests, while "could" is used for more polite
and formal requests.
o "Can you close the door?" (Direct and informal)
o "Could you close the door, please?" (Polite and formal)
2. Expressing Possibility
"Can" refers to a general possibility or capability.
o "You can learn a new language at any age." (General capability)
"Could" suggests a possibility that is less certain or more hypothetical.
o "We could go to the beach tomorrow if it's sunny." (Conditional possibility)
3. Talking about Ability
"Can" describes present or general ability.
o "I can drive a car." (Present ability)
"Could" indicates past ability or a hypothetical ability.
o "I could swim when I was a child." (Past ability)
o "If I practiced more, I could run a marathon." (Hypothetical ability)
4. Special Uses
1. "Can" in Negative Form
Expresses impossibility or prohibition.
o "You can't smoke here." (Prohibition)
o "That can't be true." (Impossibility)
2. "Could" in Conditional Sentences
Used to discuss potential outcomes in hypothetical situations.
o "If I won the lottery, I could buy a house." (Potential outcome)
3. "Can" in Questions
"Can" is often used in questions to ask about the possibility or ability of someone or
something.
o "Can you meet me tomorrow?" (Asking about the possibility)
o "Can this machine handle large files?" (Asking about the capability)
4. "Could" in Suggestions or Past Speculation
Used to make suggestions about what someone should do.
o "You could talk to your supervisor about the issue." (Suggestion)
Indicates speculation about what might have happened in the past.
o "He could have missed the bus." (Past speculation)
5. Conclusion
"Can" and "could" are versatile modal verbs in English, each with its distinct uses and
meanings. Understanding the differences between these two verbs is crucial for accurate
and effective communication. Whether expressing ability, possibility, permission, or
making requests and suggestions, the choice between "can" and "could" can significantly
impact the tone and clarity of a sentence.
