Questions & Answers about Мама поливает цветы на балконе.
Мама is the subject of the sentence, so it is in the nominative case (the "dictionary form" of nouns).
- Мама – nominative singular: who is doing the action? → mom
- Маму – accusative singular: whom? (as a direct object)
- Мамы – can be:
- genitive singular (of mom),
- nominative plural (moms),
- or accusative plural (for animate moms).
Here, Мама поливает… = Mom is watering… → мама must be nominative.