How do you form the past participle?

Answer 1

First, look in a dictionary or similar reference of adequate size to determine whether the verb has an irregular past participle shown. (There are lists of such verbs in Cassell's English-French and English-German dictionaries, and probably in others.) If the verb has an irregular past participle, use that.

Otherwise, the verb is regular, and its past participlecan be formed by following these rules, in order:

(1) If the third person singular present indicative form of the verb ends in the letter "e", add "d" to the third person singular present indicative spelling to obtain the past participle.

(2) If the third person singular present indicative form of the verb ends in the letter "y" and the letter "y" is not immediately preceded by a vowel, change the "y" in the third person singular present indicative spelling to "ied" obtain the past participle.

(3) In all other instances, add "ed" to the third person singular present indicative spelling to obtain the past participle. It may be necessary also to double any final consonant of the third person singular present indicative spelling to obtain the properly spelled past participle. This is particularly likely if the final consonant is preceded by a single vowel in the third person singular present indicative spelling. If not sure of whether to double such a consonant or not, look in a reference!.

Answer 2

To form the past participle in English, you typically add "-ed" to regular verbs (e.g., walked, talked) and follow irregular patterns for irregular verbs (e.g., eaten, written). It is used in various tenses like present perfect and past perfect.