Question

When I came home my mom was cooking dinner for us. (почему past continuous?)

Answer 1

Оооо это изи
смотри, то что мама  готовила, это продолжительное действие, поэтому мы используем past continuous, a past simple в первой части используем, ибо действие не продолжительное. я вошел и все. я не минут двадцать вхожу

Answer 2

Past continuous-Прошедшее продолженное
Когда действие происходит в прошлом но в определённый момент времени и действия!
Например:Я пришёл домой когда мама готовила.
Я пришёл-значит прошедшее время
Когда мама готовила-определённый момент.

Answer 3

The use of the past continuous tense in the sentence "When I came home, my mom was cooking dinner for us" is appropriate because it conveys that the action of cooking dinner was in progress at a specific point in the past. In this case, when you arrived home, your mom was already in the middle of the activity of cooking dinner.

The past continuous tense (also known as the past progressive tense) is used to describe actions that were ongoing or in progress at a particular moment in the past. It helps to set the scene and provide context for the actions taking place in the past. In your sentence, it helps to convey the idea that your mom was in the process of cooking dinner when you arrived home, which adds depth to the narrative.