How do you form the past and past participle of verbs?

Answer 1

For regular verbs that do not end in 'e', or a consonant followed by a 'y', you add 'ed' to form both the past and the past participle:

To jump, I jumped, I have jumped.
To fetch, I fetched, I have fetched.
To defend, I defended, I have defended.

For regular verbs that end in 'e', you add 'd' to form both the past and the past participle:

To hope, I hoped, I have hoped.
To promise, I promised, I have promised.
To devise, I devised, I have devised.

For regular verbs that end in a consonant followed by a 'y', you change the 'y' into 'i' and add 'ed' to form both the past and the past participle:

To sally, I sallied, I have sallied.

To bloody, I bloodied, I have bloodied.

For irregular verbs, you must learn each one individually. There are some patterns that may help you, but you must always beware of exceptions (English has a lot of those).

Here is one example of a pattern. Many monosyllabic verbs with an 'i' in the infinitive form the past and the past participle by changing the vowel to an 'a' and a 'u' respectively:

To sing, I sang, I have sung.
To drink, I drank, I have drunk.
To swim, I swam, I have swum.

But:
To swing, I swung (rarely 'I swang'), I have swung.

Answer 2

To form the past tense of regular verbs in English, you typically add "-ed" to the base form of the verb (e.g., "walked," "played"). For irregular verbs, the past tense forms are unique and must be memorized (e.g., "went," "ate"). The past participle is usually the same as the past tense for regular verbs ("jumped" for both past tense and past participle), while for irregular verbs, it varies ("gone" for past participle of "go").