1. Ability in the Past: "Could" is used to indicate past ability or capability.
- When I was younger, I could run faster.
- She could speak French fluently when she lived in Paris.
2. Polite Request: "Could" is commonly used to make polite requests or ask for permission.
- Could you please pass me the salt?
- Could I borrow your pen for a moment?
3. Possibility or Uncertainty: "Could" can express a possibility or uncertainty.
- It could rain later, so bring an umbrella.
- He could be at the library; let's check there first.
4. Conditional Sentences: "Could" is used in conditional sentences to express hypothetical situations or outcomes.
- If I had more time, I could help you with your project.
- She could travel the world if she won the lottery.