1. Peter can lift the bucket of water.                  (Present)
2. Peter is able to lift the bucket of water.        (Present)
3. Peter could lift the bucket of water.               (Past)
4. Peter was able to lift the bucket of water.    (Past)

NB: The modals “can, could, to be able to” are used to express ability.

Ability is what someone can do.

Can                                       

Are/ Am/ is able to        Present

Could

Were/ was able to         past

Exercise

Fill in the gaps with the appropriate form as directed above to express ability.

1. Today morning, I __________ to trek to school.
2. She says she is __________ answer all the questions.
3. My sick cousin __________ to walk alone to the hospital yesterday.
4. My younger brother __________ spell all the words you are reading.
5. Nurses __________ take good care of their patients.

ANSWERS

1. Was able to
2. Able to
3. Could
4. Can
5. Can