Modals In The Past Form

1. Could + Verb base
• To express ability to do something
Example: I could make you happy
• To express ability, subject to certain conditions which probably do not exist
Example: When I was ten, I could spend 4 hours to study
• To express polite request
Example: Could I go to your home?
• To express polite request
Example: Could you take my phone, please?
• To express polite offer
Example: You could borrow my pen till this afternoon
• To express polite suggestion
Example: Could I do my homework tomorrow?
• To express possibility
Example: She could get high fever

2. Would + Verb base
• To express wish, request (more polite than will)
Example: Would you turn on my radio?
• To express habits in the past
Example: When I was thirteen, I would go to Disneyland Hongkong every month
• Insert rather into the pattern and use this expression to express preferences
Example: I would rather visit Korea than Netherland

3. Should + Verb base
• To give definite advice (advisability)
Example: You should bring your umbrella
• To express the subject’s obligation or duty
Example: They should

4. Might + Verb base
• To tell possibilities
Example: I might make a toy for my brother
• To express polite request
Example: Might I pay for you later?
• To express hesitant offer
Example: Might I help you to wash your clothes?