Dear students,

Please copy the following lesson into the Lesson section of your English copybook:

We use COULD to express:

1. Ability
2. Permission to do something.

• (1) He could swim a distance of 10 miles without getting tired.
• (2) They could play as long as they wanted with expensive toys.

You can alternatively use BE ABLE TO to express ability:

• Lower class children were not able to read or write.

And BE ALLOWED TO to express permission:

• They were allowed to have big pets like ponies, for example.

BE FORCED TO expresses constraint:

• They were forced to work.

Finally, HAVE TO expresses obligation in the positive form:

• They had to attend school until they were 10.

And lack of obligation in the negative form:

• They didn’t have to go to school.