Mi a különbség a wasn't és a didn't között?

A wasn't a létige tagadása, az "am not" és az "is not" múlt ideje (nem voltam, nem volt - E/1 és E/3, ahogy az egyes írja)

didn't - a don't és doesn't múlt idejű alakja, ha ezeket tudtad használni jelenben, könnyű dolgod lesz; alapvetően minden olyan mondatban ezt használod, ahol van valami cselekvést jelentő ige

pl.

I (not, be) at home yesterday. > I wasn't at home yesterday.

He (not, be) at school last week. > He wasn't at school last week.

I (not, do) my homework. > I didn't do my hw.

They (not, travel) to Spain. > They didn't travel to Spain.

Ugyanez, ha jelen idejű mondatot ad meg a tanár.

I'm not at school now. > I wasn't at school yesterday.

She isn't nice. > She wasn't nice.

We don't go to school on Sunday. > We didn't go to school...

She doesn't play the drums. > She didn't play the drums.