- In English there are four principal parts, or forms, of a verb.
If you study foreign languages, many languages have six forms of each verb for each tense. That's a lot of memorizing. English uses helping verbs and the four principal parts to show the tenses.
|base/present||present participle||past||past participle|
- Base/Present - same as infinitive without to. Add -s to form third person singular.
- Present Participle - add -ing.
- Past - add -ed
- Past Participle - add -ed
Note: Participles function as part of a verb phrase. They can't be used as verbs by themselves. They must have a helping verb in order to make sense.
My sister is walking to school today.
Before leaving, we made sure we had walked the dog.
When adding endings to verbs, you sometimes have to change the spelling.
Single syllable verbs generally double the consonant when adding -ing and -ed.
shop + s = shops, shop + ing = shopping, shop + ed = shopped
Verbs that end with a single vowel and a consonant that stress the end of the word usually double the consonant before adding -ing and -ed.
refer + s = refers, refer + ing = referring, refer + ed = referred
To add -s or -ed to verbs that end in consonant y, change y to i before adding the ending. To add -ing, don't change the y.
carry + s = carries, carry + ing = carrying, carry + ed = carried
To add -ed or -ing to verbs that end in silent e, drop the e before adding -ed or -ing.
amaze + s = amazes, amaze + ing = amazing, amaze + ed = amazed
Verbs that end in a vowel followed by an l usually double the l before adding -ed or -ing in British English, but usually don't in American English.
American: travel + s = travels, travel + ing = traveling, travel + -ed = traveled.
British: travel + s = travels, travel + ing = travelling, travel + -ed = travelled
Verbs that end in c usually add k before adding endings.
frolic + s = frolics, frolic + ing = frolicking, frolic + ed = frolicked
If the verb ends with a single vowel before a consonant, but the last syllable is not stressed, don't double the consonant.
wander + s = wanders, wander + ing = wandering, wander + ed = wandered
Verbs with a double vowel before a consonant do not double the consonant.
retreat + s = retreats, retreat + ing = retreating, retreat + ed = retreated