Modals in the past form
| Modals | 
   | present | Past | 
   | can | could | 
   | will | would | 
   | shall | should | 
   | may | might | 
 
1. Could + Verb base
        to offer  suggestions or possibilities
Example:      
 Patrick                  :  Oh, no! I left my  shorts.
Spongebob           : Don’t worry, Patrick. You could borrow my shorts.Asmi                     : I’m having trouble with English.
Randah                : Why don’t you ask Agnes? Perhaps she could help you.
        to indicate that the ability existed in the past but doesn’t  exist now.
Example:       
Tasya                  : Ras, can you climb the durian tree?
Rasya                :  Well… I could climb durian tree when I was so young.
              But I think I’m   too  heavy to climb it.
Mia                    : Grandpa, what could  you do when you were younger?
Grandpa            :   When I was younger, I could swim across the big river
to express polite requests  
Example:           Could I  borrow your pencil (please)?
  
                             Could you lend me your jacket now?
  
                             Could you please close the door?
  
                             Could you pass the salt?
  
2. Would + Verb base
  
         for an action that was repeated regularly  in the past
  
Example:        
When I was a child, I would visit my  grandparents every weekend.
  
On Sundays, when I was a child, we would all get up early  and go fishing.
  
        insert rather into the pattern and use this expression to express preferences
  
Example:
Justin     :  What would you rather do in the weekend, go  to the party or stay home?
  
Eminem :   I would rather go to the party than stay home. 
  
         
  
Angel     :   Which country would you rather visit?
  
Maria       :  I would rather visit Italia  than Somalia.
  
        to express  polite requests
  
Example:      
 Andi      :  Would you mind cycling with me, Kala?
  
Kala     :  No, not at all. It  would be nice.
  
Mikola  : Would you please  pass the helmet, Bella?
Bella    : No problem
to give definite advice (advisability)