As you can see, regular verbs add ed to make the past tense (work / worked) and irregular verbs change their form entirely (go / went). The most important verb to learn first in the past tense is "be."

Be - Past Tense

Singular	Plural
I was	We were
You were	You were
He was	They were
She was
It was
To make the negative, use "did" + "not" (didn't) + the main verb in the simple form:
Singular		Plural
I did not learn		We did not learn
You did not learn		You did not learn
He did not learn		They did not learn
She did not learn
It did not learn

Irregular Verb: Have

Subject + ________

(irregular verbs take many different forms in the past tense)

Singular	Plural
I had	We had
You had	You had
He had	They had
She had
It had