Negative pronouns and adverbs: никто́, ничего́, никогда́
The ни- series is unstressed and needs не on the verb; the не- series is stressed and stands alone; double negation is compulsory.
There are two series and they are kept apart by stress. In the ни- series the prefix is unstressed and the stress falls on the second element: никто́, ничего́, никако́й, никогда́, нигде́, никуда́, ниотку́да, ниче́й. In the не- series the prefix carries the stress: не́кого, не́чего, не́кому, не́чем, не́ о чём. The two are not interchangeable and the difference is grammatical, not stylistic.
The ни- series is used inside a clause that has a verb, and that verb must carry не as well: Никто́ не пришёл, Я ничего́ не зна́ю, Она́ никогда́ не опа́здывает, Мы нигде́ не останови́лись. This is the obligatory double negation, and it is the hardest habit for an English speaker to acquire, because English makes you choose one. Russian does not: every negative element in the clause stays negative, however many there are — Никто́ никогда́ ничего́ мне не сказа́л. There is no equivalent of 'any-' words; 'anything' and 'nothing' are the same Russian word in different frames.
The не- series appears only in two words, не́кого and не́чего, and only in infinitive constructions where there is nobody or nothing available for the action: Не́кого спроси́ть (there is nobody I can ask), Нам не́чего де́лать (there is nothing for us to do), Ему́ не́ с кем говори́ть (he has nobody to talk to). There is no finite verb in the clause at all, which is exactly why the stress moves to не-. Note the split forms when a preposition intervenes: не́ с кем, не́ у кого, не́ о чём.
Declension and word order behave as you would expect. Никто́ and ничего́ decline like кто and что — никто́, никого́, никому́, никого́, нике́м, ни о ком — and the same goes for ничто́ and the adverbs. A preposition splits the word in two and the ни goes in front of it: ни у кого́, ни с кем, ни о чём, ни для чего́. The emphatic ни … ни means 'neither … nor': Ни чай, ни ко́фе — спаси́бо. And a bare ни plus the Genitive gives the curt prohibition: Ни слова́! Ни ша́гу!
Examples
- Никто́ не зна́ет отве́та. Nobody knows the answer. Listen in Russian: Slow in Russian: Никто́ не зна́ет отве́та.
- Я ничего́ не понима́ю. I don't understand anything. Listen in Russian: Slow in Russian: Я ничего́ не понима́ю.
- Она́ никогда́ не опа́здывает. She is never late. Listen in Russian: Slow in Russian: Она́ никогда́ не опа́здывает.
- Нам не́чего де́лать. There is nothing for us to do. — the stressed не- series, with no finite verb Listen in Russian: Slow in Russian: Нам не́чего де́лать.
- Ни чай, ни ко́фе — спаси́бо. Neither tea nor coffee, thank you. Listen in Russian: Slow in Russian: Ни чай, ни ко́фе — спаси́бо.
- Я не был ни в Пра́ге, ни в Берли́не. I have been neither to Prague nor to Berlin. Listen in Russian: Slow in Russian: Я не был ни в Пра́ге, ни в Берли́не.