Новая грамматическая тема: конструкции «кто бы ни», «что бы ни» и «куда бы ни» с частицей «бы» означают «неважно кто / что / куда».

Бы is a particle that normally forms the subjunctive / conditional mood in Russian (something like English would / could / might).

In кто бы ни / что бы ни / куда бы ни, бы still marks the whole clause as hypothetical / general rather than about one specific, known situation. That’s why the construction means “no matter who / what / where” – it talks about any possible person/thing/place in general.

Example:

• Кто бы ни позвонил, не отвечай.
  No matter who calls, don’t answer.

There’s no direct word-for-word equivalent of бы in the English translation; it’s part of the fixed Russian pattern that creates this “whoever / whatever / wherever” meaning.

In кто бы ни / что бы ни / куда бы ни, ни is not a simple negation like не.

Here, ни acts more like an emphasizer that helps form an indefinite / concessive meaning:

• кто бы ни ≈ whoever / no matter who
• что бы ни ≈ whatever / no matter what
• куда бы ни ≈ wherever / no matter where

So it’s closer in function to the -ever in whoever / whatever / wherever, not to English not.

Of course, ни can participate in real negation in other structures (e.g. никто, нигде, никогда), but in this particular pattern it’s part of the “no matter X” construction rather than simple negation.

In real sentences, these phrases introduce a subordinate clause that usually contains a past-tense verb + бы (that’s the usual form of the Russian subjunctive):

• Кто бы ни пришёл, я буду рад.
  Whoever comes, I’ll be glad.

• Что бы ни случилось, я буду с тобой.
  Whatever happens, I’ll be with you.

• Куда бы ты ни поехал, я поеду с тобой.
  Wherever you go, I’ll go with you.

Pattern:

• кто/что/куда + бы + ни + (past-tense verb + бы) is the “canonical” formal pattern,
  but in everyday speech you often just see:
  
  • Кто бы ни пришёл…
  • Что бы ни случилось…
  • Куда бы ты ни пошёл…

The main clause (I’ll be glad / I’ll be with you / I’ll go with you) can be in any appropriate tense; it doesn’t have to contain бы.

No. The word order in this construction is essentially fixed:

• ✅ кто бы ни
• ✅ что бы ни
• ✅ куда бы ни

and not:

• ❌ кто ни бы
• ❌ ни кто бы
• ❌ куда ни бы

Also, бы is a clitic particle that normally comes right after the first stressed word in a clause, and this pattern has become a fixed idiom with the order interrogative word + бы + ни. Changing the order sounds ungrammatical or extremely marked.

The case of the question word depends on its role in the subordinate clause, just like in any normal sentence:

• Кто бы ни пришёл… – subject → nominative.
  Whoever comes…

• Кого бы ни позвали… – object → genitive / accusative (here genitive after ни, but often corresponds to English object).
  Whoever they may invite…

• Куда бы ни пошёл… – direction → куда (directional adverb).
  Wherever (to whatever place) he may go…

More examples:

• Кому бы ни звонили, никто не отвечает.
  Whoever they call, no one answers.

• Чего бы он ни хотел, мы постараемся помочь.
  Whatever he may want, we’ll try to help.

So you choose the form of кто/что/куда/etc. exactly as you would if it were a normal question: Who is coming? → Кто?, Whom did you see? → Кого?, etc. Then you insert бы ни after it.

They are close in meaning but not identical.

1. кто бы ни / куда бы ни introduce a clause and often have a slightly more formal or literary feel:

   • Кто бы ни пришёл, я буду рад.
     Whoever comes, I’ll be glad.
   • Куда бы ты ни поехал, я тебя найду.
     Wherever you go, I’ll find you.

2. кто угодно / куда угодно / что угодно are noun/adverbial phrases, often more colloquial, and they don’t by themselves introduce a subordinate clause:

   • Мне подойдёт кто угодно.
     Anyone will suit me.
   • Поехали куда угодно.
     Let’s go anywhere / wherever.

Sometimes you can choose either, but:

• кто бы ни fits best at the start of a dependent clause with a verb.
• кто угодно is more like a standalone “anyone / whoever” as a noun phrase.

This is a very common confusion.

1. Что бы ни (three words) = “whatever / no matter what”

   • Что бы ни случилось, звони мне.
     Whatever happens, call me.

   Here что is a question word, бы is the subjunctive particle, and ни helps form the “no matter what” meaning.

2. Чтобы не (two words: чтобы

   • не) usually = “so that … not” / “in order not to” or sometimes “so as not to / to avoid”:
   • Я закрыл окно, чтобы не замёрзнуть.
     I closed the window (in order) not to freeze.
   • Он ушёл пораньше, чтобы не опоздать.
     He left early so as not to be late.

So:

• что бы ни = whatever / no matter what
• чтобы не = so that not / in order not to

The meaning and the grammar are completely different, even though they sound almost the same.

The verb in кто бы ни… must agree (at least in principle) with the real subject you have in mind. In practice:

• Generic / unknown person → usually masculine singular by default:

  • Кто бы ни пришёл, я буду рад.
    Whoever comes, I’ll be glad. (generic “whoever”)

• If you clearly mean a woman, you can use feminine:

  • Кто бы ни пришла, я буду рада.
    (Said by a woman about an expected female visitor.)

• If you clearly mean plural people, you can use plural:

  • Кто бы ни пришли, я буду рад.
    Whoever comes (whoever they are), I’ll be glad.

The masculine singular form is the most common, “default” option when the person is completely unspecified, but agreement can change if the context is clear.

It’s not “negative” in the sense of not; instead, it usually expresses a kind of concession or indifference to which specific option is realized:

• Кто бы ни позвонил, я не отвечу.
  No matter who calls, I won’t answer.

• Что бы ни случилось, я с тобой.
  Whatever happens, I’m with you.

• Куда бы ты ни поехал, я найду тебя.
  Wherever you go, I’ll find you.

The key idea is:
> The result / my attitude is the same, regardless of which specific person/thing/place it is.

So it’s about “it doesn’t matter which”, not simple negation.

You can definitely use it with many other interrogative words, especially:

• где бы ни – wherever / no matter where
• когда бы ни – whenever / no matter when
• как бы ни – no matter how (often “however much / however hard”)
• сколько бы ни – no matter how much / however many

Examples:

• Где бы ни был, звони родителям.
  Wherever you are, call your parents.

• Когда бы ты ни пришёл, я буду дома.
  Whenever you come, I’ll be at home.

• Как бы ни было трудно, не сдавайся.
  No matter how hard it is, don’t give up.

• Сколько бы ни стоило, я это куплю.
  No matter how much it costs, I’ll buy it.

So the pattern is quite productive with many “question words” (кто, что, где, куда, когда, как, сколько, etc.).

It’s absolutely normal in everyday spoken Russian and in writing.

• In everyday speech, you’ll hear sentences like:

  • Что бы ни случилось, позвони мне.
  • Куда бы ни поехали, берём детей.

• In writing (especially formal or literary), it’s also very common because it’s a neat and precise way to say “no matter who/what/where/when…”.

So you can safely use it in both casual conversation and more formal contexts. It does not sound archaic or bookish by itself.

The main clause does not have to use бы. It can be in any tense/mood that fits the meaning.

• Without бы in the main clause:

  • Кто бы ни позвонил, я не отвечу.
    Whoever calls, I won’t answer.

• With бы in the main clause (more hypothetical, polite, or conditional):

  • Кто бы ни позвонил, я бы не ответил.
    Whoever called, I wouldn’t answer.

So кто бы ни / что бы ни / куда бы ни only forces the subordinate clause into the subjunctive-like form; the main clause is free to be present, future, past, or conditional depending on what you want to say.