What are the differences between:

Водой , воды and вода ?

Question

What are the differences between:

Водой , воды and вода ?

Answer

This is summary of "Падежи".
They tilt the word in different directions (there are 6 падежей in total):
Именительный - вода (answers the question "who?", "what?" - "кто", "что");
Родительный - воды (answers the question "whom?", "what?" - "кого", "чего");
Дательный - воде (answers the question "to whom?", "what/which?" - "кому", "чему");
Винительный - воду (answers the question "whom/who?", "what?" - "кого", "что");
Творительный - водой (answers the question "by whom?", "than?" - "кем", "чем");
Предложный - о воде (answers the question "about whom?", "about what?" - "о ком", "о чём").

The approximate meaning is conveyed in English.

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