Learn Hardcore Russian: Если я пью воду, я становлюсь счастливым.

Если means if and introduces a conditional clause. Here, it sets the condition under which the main statement applies: if I drink water, then I become happy.

Why is the noun вода changed to воду in this sentence?

The verb пью (I drink) requires a direct object in the accusative case. For feminine nouns like вода, the accusative singular form becomes воду. This change marks the noun as the object of the action.

Why is the adjective счастливым in the instrumental case?

In Russian, when using verbs like становиться (to become) to indicate a transformation or state change, the predicate adjective is typically put in the instrumental case. Счастливым (happy) in the instrumental expresses the new state that the subject assumes upon drinking water.

What is the meaning and form of the verb становлюсь?

Становлюсь is the first-person singular present tense form of the verb становиться, which means to become. It indicates that the change into a happy state happens as a current or habitual result of the condition being met.

How is the sentence structured, and why is there a comma?

The sentence is a conditional statement composed of a subordinate clause (Если я пью воду) and a main clause (я становлюсь счастливым). The comma is used to separate these two clauses according to standard Russian punctuation rules for complex (conditional) sentences.

Would the adjective счастливым change if the speaker were female?

Yes, it would. In Russian, adjectives must agree with the gender of the subject. A female speaker would use the feminine instrumental form, saying: Если я пью воду, я становлюсь счастливой.