The past participle of a word is formed by adding -d or -ed to the base form of the verb.
Whether to add -d or -ed depends on the last letters of the base form of the verb. This can be determined for the most part from two guidelines.
>If the base form ends in -e, then it will most like be made a past participle by adding -d. >If the base form ends in any other letter, then it will most likely be made a past participle by adding -ed.
In the word 'jump', the ending of the base form of the verb is -p. Therefore, in order to make it a past participle, we will need to add an -ed to the end of the base form.
