The Past Form and the Past Participle Form of Regular Verbs

For verbs ending in e, add d.

For one-syllable verbs ending in a vowel plus a consonant other than w, x, or y, double the last consonant and add ed.

For some verbs ending in a vowel plus w, add ed.

Exceptions: blow, draw, grow, outgrow, overdraw, overthrow, saw, sew, show, sow, strew, throw, withdraw.

For verbs ending in a vowel plus x, add ed.

For some verbs ending in a vowel plus y, add ed.

Exceptions: buy, gainsay, inlay, lay, mislay, overlay, overpay, pay, prepay, repay, say, slay, underpay, unsay.

For two-syllable verbs ending in a vowel plus a consonant other than w, x, or y, double the last consonant and add ed when the stress is on the last syllable.

The last consonant is not doubled when the stress is on the first syllable.

Please note that in British English, the consonant l is doubled, even though the stress is on the first syllable.

For verbs ending in a consonant plus y, change the y to i and add ed.

For verbs ending in ic, change the c to ck and add ed.