We can use both “can” and “could” to ask for a request, but they have different levels of politeness and formality. “Can” is more casual and direct, while “could” is more polite and indirect.
When you use “could”, you are implying that you are not sure if the person is able or willing to help you, so you are giving them a choice to refuse. When you use “can”, you are assuming that the person is able and willing to help you, so you are making a direct request.
- Could you help me with this problem, please? (This is more polite because you are not sure if the person can or wants to help you, and you are saying please.)
- Can you help me with this problem? (This is less polite because you are expecting the person to help you, and you are not saying please.)
Tip
The connection between politeness and the past simple is that the past simple is often used to express hypothetical or unreal situations, which are more polite than real or certain situations.
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