Learn Hardcore Russian: Выключи свет, нажав соответствующую кнопку пульта. - Turn off the light by pressing the corresponding button on the remote.

нажав is the perfective gerund (деепричастие совершенного вида) of the verb нажать (“to press”). In English it corresponds to “by pressing” or “after pressing.” It shows that the pressing happens before or at the same time as the main action (выключи). Russian gerunds require a comma when they form a clause like this.

Why is свет in the accusative case rather than the nominative?

Because свет (“light”) is the direct object of the imperative verb выключить (“to turn off”). Transitive verbs in Russian take their object in the accusative; here it answers the question “Turn off what?” → “the light.”

What case is кнопку, and why is it used here?

кнопку is the accusative singular of кнопка (“button”). The gerund нажав comes from нажать кнопку (“to press a button”), so кнопку is the direct object of нажать and must be in the accusative.

Why is пульта in the genitive case?

пульта is the genitive singular of пульт (“remote control”). It indicates possession or “of-ness” (the button of the remote). In Russian, the noun that follows another noun to show “X of Y” typically goes into the genitive case.

What does соответствующую mean, and why does it change form?

соответствующую is the accusative feminine singular form of the adjective соответствующий, meaning “appropriate,” “corresponding,” or “the correct one.” It agrees in gender, number, and case with кнопку (feminine, singular, accusative).

Why is there a comma before нажав, and can I omit it?

In Russian, any gerund clause (деепричастный оборот) is set off by commas. Here нажав соответствующую кнопку пульта is an adverbial participle phrase modifying выключи, so you must use a comma. Omitting it would be a punctuation mistake.

Why use the perfective gerund нажав instead of the imperfective нажимая?

The perfective gerund (нажав) focuses on a single, completed action (“once you press”). The imperfective gerund (нажимая) would stress a simultaneous or ongoing action (“while pressing”), which doesn’t fit an instruction that expects a quick, one-time press.

Why is the imperative выключи used instead of выключай, and what’s the difference?

выключи is the perfective imperative of выключить (“to turn off”) and implies completion of the action—“go and turn it off.” выключай would be the imperfective imperative of выключать, implying a repeated or continuous action (“keep turning off”), which sounds odd here. The perfective imperative is standard for one-off commands.