Verbs

Past of regular verbs

To form the past simple of regular verbs, add -ed to the infinitive.
When the infinitive ends in e add -d.
When the infinitive ends in y, the y changes to i and then add -ed.

Infinitive	Past simple
finish	finished
decide	decided
study	studied

To form the negative past simple use didn't + infinitive.

• I didn't finish the book.

To form a past simple question use did + infinitive.

• Did you finish the book?
  NOT: Did you finished the book?