part of speech: auxiliary verb
definition 1: used to express that there was ability to do something in the past, or that an action or state was possible in the past.
- My father could play tennis very well when he was young.
definition 2: used in present or future time to talk about some action or state that is possible but not certain; often used in polite requests or offers.
- I could help you with it tomorrow, if you’d like.
- Could I speak to the doctor, please?