Questions & Answers about Мама позвала нас домой.
Мама is in the nominative case because it is the subject of the sentence – the one performing the action.
- Мама позвала… – Mom called… (Mom is the one doing the calling.)
- If мама were the object, you would see маму (accusative), e.g. Я увидел маму – I saw mom.
So here:
- мама = nominative, subject
- позвала = verb, what the subject did
- нас = object, whom she called
- домой = direction, where she called us to
Позвала is:
- Past tense
- Perfective aspect
- Feminine singular form
- From the verb pair звать / позвать – to call (someone by voice, to call over)
Roughly:
- звать – imperfective: to be calling, to call repeatedly, the process
- позвать – perfective: to call once / to have called (completed action)
So мама позвала is like Mom called (once, successfully, completed).