Regular vs Irregular verbs

The main difference between regular and irregular verbs is how their past tense and past participle forms are created: 
Regular verbs
The past tense and past participle of regular verbs are formed by adding the suffix "-ed" to the infinitive of the verb. For example, the past tense of "walk" is "walked". 
Irregular verbs
The past tense and past participle of irregular verbs are formed in some way other than by adding "-ed" to the infinitive of the verb. Irregular verbs have multiple forms and do not follow a pattern, so they must be memorized. For example, the past tense of "sat" is an irregular verb.
Some verbs have both a regular and an irregular form, such as "burn" and "learn". The regular form is more common in American English, while the irregular form is more common in British English. 

Some regular verbs can change their spelling in other ways, but they still follow predictable patterns.

Spelling rules to frame regular verb forms

👉Short verbs (one syllable) ending with a consonant-vowel-consonantDouble the final letter and add “-ed”

chop → chopped

drag → dragged

👉Longer verbs (more than one syllable) that end with a consonant-vowel-consonant and have a stressed final syllable

Double the final letter and add “-ed”

permit → permitted

admit → admitted

👉Ends in a consonant + y

Remove the “y” and add “-ied”

identify → identified

empty → emptied

👉Ends in “-e”Add “d”

chase → chased

frame → framed

👉All other endings

Add “-ed”

delay → delayed

assist → assisted