MODALS: Uses of could

1. POLITE REQUEST
2. PERMISSION
3. GUESS
4. PAST ABILITY / INABILITY
5. PAST POSSIBILITY THAT DIDN’T HAPPEN
6. PRESENT IMPOSSIBILITY
7. PAST IMPOSSIBILITY
 EXAMPLES: 

1. POLITE REQUEST - "Mom, could I go to the mall?"
2. PERMISSION - "My mom said I could go to the mall."
3. GUESS - "The answer could be eight."
4. PAST ABILITY / INABILITY - "I could not do 20 push ups until I started exercising regularly."
5. PAST POSSIBILITY THAT DIDN’T HAPPEN - "I could have dated her in middle school."
6. PRESENT IMPOSSIBILITY - "You could not beat me in chess."
7. PAST IMPOSSIBILITY - "You could not reach the top shelf when you were five."