The Present Simple Past
In spoken English, the following contraction is often used:
Without Contraction
With Contraction
did not didn't
For example:-
I/he/she/it/you/we/you/they did not did not have did not read did not like did not eat did not drink
I/he/she/it/you/we/you/they didn't didn't have didn't read didn't like didn't eat didn't drink
In order to change an affirmative statement into a negative statement, did not is placed after the subject, and the form of the verb is changed to the bare infinitive.
Positive statement Negative statement
I worked. I didn't work.
You worked. (singular 1 and plural 1+) You didn't work.
He/She worked. He/She didn't work.
It worked. It didn't work
We worked. We didn't work.
They worked. They didn't work.