Practice
Could, would, or should: ability, polite choices, and advice
Sign in to saveOne small word changes the message. I could carry the box describes a possibility or ability. I would carry the box if I had time gives a conditional choice. You should carry the box safely gives advice.
Choose could, would, or should when you mean past ability or possibility, a polite request or preference, or advice.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
Would you prefer water or juice? /wʊd juː prɪˈfɜː ˈwɔːtə ɔː dʒuːs/
The short answer
Use could for past ability, possibility, or a polite request. Use would for a polite offer, invitation, preference, or imagined result. Use should for advice. After each modal, use the base verb: could help, would choose, should rest.
You should save the document before closing it.
Why it works: Should gives practical advice, and save is the base verb.
5 more examples
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When I was ten, I could swim across the pool.
Could describes the speaker's ability at a time in the past.
Not this:I
can swimacross the pool now. What changes: Can describes a present ability, while could places this ability in the past. -
Could you email me the address, please?
Could makes a request sound polite. It does not mean that the request happened in the past.
Not this:
Can you emailme the address? What changes: Can is also natural for a request, but could is usually more formal or more polite. -
I would choose the earlier train if the fares were the same.
Would describes a preference in an imagined situation.
Not this:I
will takethe earlier train tomorrow. What changes: Will states a future decision, while would depends on the stated condition. -
Would you prefer water or juice?
Would you prefer is a polite way to offer a choice.
Not this:
Do you wantsome water? What changes: This direct question is possible, but a form with would is more polite in an offer. -
You should back up your work before updating the computer.
Should gives useful advice. The speaker recommends the action but does not make it an order.
Not this:You
must back upyour work before updating the computer. What changes: Must makes the action necessary in the speaker's message.
Read the full guide
Ask what the speaker is doing before you choose the modal. Are they describing an ability or possibility, speaking politely about a choice, or recommending an action? The answer usually points to could, would, or should.
Start with the speaker's purpose
Could, would, and should all come before a base verb, so grammar alone will not choose the right one. Look at the speaker's purpose. Could often concerns ability, possibility, or a polite request. Would is common when someone offers, invites, or imagines a choice. Should gives advice.
You should call the clinic before you visit.
The speaker recommends calling first. This is advice, so should fits.
Which modal fits a recommendation about a sore throat: could, would, or should?
Use should: You should drink some water and rest.
Use could for ability, possibility, and polite requests
Could often describes an ability in the past. It can also say that something is possible, though not certain. In a question, could is a polite way to ask another person to do something. The surrounding situation tells the listener which meaning is intended.
My grandfather could speak three languages when he was young.
Could speak describes an ability that belonged to an earlier time.
The delay could affect our arrival time.
Could affect leaves the result open. It does not say that the delay will definitely affect the arrival time.
Make this request more polite: You send the file again?
Write: Could you send the file again, please?
Use would for polite choices and imagined results
Would is useful when you speak politely about what you want, offer, or prefer. Would you prefer starts a polite choice. I would like is polite when you ask for something. Would also describes the result of an imagined condition, often after an if clause.
I would like a seat near the window, please.
Would like makes the request polite. The speaker is asking for a preference, not reporting a future plan.
If the store were open, I would buy a charger.
The store is not open in this imagined situation, so would buy describes the possible result.
Which question offers a guest a choice: Would you prefer tea or coffee? or Should you prefer tea or coffee?
Use Would you prefer tea or coffee? It offers a polite choice.
Use should for advice and expectations
Use should when you think an action is sensible or helpful. It gives advice without the force of a rule. Should can also show an expectation when the speaker thinks something is likely to happen or be true.
You should read the instructions before you begin.
The speaker recommends reading first. The listener still makes the decision.
The bus should arrive in ten minutes.
Should arrive shows an expected result. The speaker does not promise an exact arrival time.
Choose the advice: You ____ wear a coat because it is cold.
Use should: You should wear a coat because it is cold.
Keep the verb form simple
After could, would, or should, use the base form of the verb. Do not add to, -s, or -ing. This rule stays the same with I, you, he, she, we, and they. Make a negative with not, and start a question with the modal.
She could meet us after work.
Meet is the base form after could. Do not write could meets or could to meet.
Should I bring my passport?
The modal should comes before the subject I to form a question.
Correct this sentence: He should to call the office.
Write: He should call the office. Should is followed by the base verb call.
Before you go
Remember this
Choose could for past ability, possibility, or a polite request. Choose would for polite offers, invitations, preferences, and imagined results. Choose should for advice or an expectation. Then check the grammar: modal plus base verb.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Could, would, or should: ability, polite choices, and advice"
What is the main difference between could, would, and should?
Could often expresses past ability, possibility, or a polite request. Would is common in polite offers, invitations, preferences, and imagined results. Should gives advice or an expectation. Choose the modal from the speaker's purpose, then use the base form of the next verb.
When I was ten, I could swim across the pool.
Does could always refer to the past?
No. Could can refer to a past ability, but it can also make a polite request or describe a present or future possibility. Could you email me the address, please? is a request. The delay could affect our arrival time describes a possible result.
I can swim across the pool now.
When do I use would for a polite offer?
Use would to make a polite offer, invitation, or choice. Would you prefer water or juice? offers a choice. I would like a seat near the window, please makes a polite request. These forms are often more polite than a direct question with do you want.
Could you email me the address, please?
How is should different from must?
Should recommends an action, while must presents it as necessary. You should back up your work gives advice. You must back up your work makes backing up necessary in the speaker's message. The difference is the strength of the instruction.
Can you email me the address?
What verb form comes after could, would, and should?
Use the base form of the verb after each modal: could help, would choose, and should rest. Do not add to, -s, or -ing. In a question, put the modal before the subject, as in Should I call first?
I would choose the earlier train if the fares were the same.