How do we form it?
The same form is used for all persons and It is formed in regular verbs by adding -ed to the infinitive:
I worked
you worked
he worked
she worked
we worked
you worked
they worked
When the verb ends in e adds only -d
love, loved
The negative of regular and irregular verbs is formed with did not and the infinitive without to:
I did not work
you did not work
he did not work
she did not work
we did not work
you did not work
they did not work
The interrogative of regular and irregular verbs is formed with did + subject + infinitive without to:
Did I work? did you work?....
Verbs ending in y following a consonant change the y in i before adding ed:
study, studied, but obey, obeyed (y following a vowel doesn't change)
Irregular verbs
They usually have a different form in the simple past form:
Infinitive: to bring to eat to see to speak
Simple past: brought ate saw spoke
Once these irregular verbs have been learnt there is no other difficulty, as irregular verbs like regular verbs have no inflexions in the past tense.