кто бы ни

The construction кто бы ни is a concessive clause (the "no matter who" construction) used to indicate that the identity of a person is irrelevant to the outcome. It is essential to become proficient in its specific syntactic and punctuation requirements.

1. Temporal Range:
While often used for future or hypothetical scenarios, it is equally common for past generalizations. In such cases, it refers to 'whoever it was' or 'whoever happened to be' at that time.

2. The Role of 'бы' vs. Indicative and Imperative:

• Кто бы ни: Used for potential, hypothetical, or generalized situations (subjunctive).
• Кто ни: Used without бы with the indicative mood (imperfective for actual repeated actions, perfective for timeless generalizations) or with the imperative mood for timeless, impersonal generalizations (e.g., 'Кого ни спроси...' - 'Whomever you ask...').

3. Spelling, Punctuation, and Set Phrases:
The phrase кто бы ни is always written as three separate words. Subordinate clauses starting with кто бы ни are generally separated from the main clause by a comma. However, there is a major exception for syntactically indivisible set phrases like кто бы то ни было (anyone at all). When acting as a single sentence member, it does not take a comma (e.g., 'Он готов был говорить с кем бы то ни было').

4. Morphological and Syntactic Requirements:

• Verb Form: The verb following кто бы ни is typically in the past tense form to form the subjunctive mood with бы (e.g., 'Кого бы я ни спросил...' or the impersonal 'Кого бы ни назначили на эту должность...').
• Verb Agreement: When кто is the grammatical subject, the past tense verb following кто бы ни is strictly masculine singular, even if referring to a woman or multiple people. However, when кто acts as a predicative complement (meaning 'whoever someone is/was'), the verb agrees with the actual subject in gender and number (e.g., 'Кто бы она ни была' or 'Кто бы ни были эти люди').
• Declension: The pronoun кто declines based on its grammatical role (e.g., кого бы ни for objects).
• Prepositions: Prepositions are placed at the very beginning of the phrase: с кем бы ни. This contrasts with negative pronouns, where the preposition is placed between the ни prefix and the pronoun root (e.g., ни с кем).
• Word Order: The particle бы typically follows the pronoun immediately, while ни must immediately precede the verb. Other words, such as the subject, are often sandwiched between бы and ни (e.g., Кого бы ты ни встретил - 'Whomever you might meet').
• The Particle 'ни': This is an intensifying particle, not a negation. The clause remains positive.
• Correlative Pronouns: The main clause often uses a correlative pronoun (like тот, все, никто) to 'catch' the whoever/whomever (e.g., 'Кто бы ни звонил, никто не отвечал' - 'Whoever called, no one answered').
• Main Clause Mood: The main clause usually remains in the indicative mood (present or future).

5. 'Кто бы ни' vs. 'Кто бы не':
Кто бы ни introduces an adverbial concessive clause ('whoever does this'). In contrast, кто бы не introduces a standard relative clause modifying a noun or pronoun in the main clause ('who wouldn\'t do this'). For example: Кто бы ни пришёл... (Whoever comes...) vs. Нет никого, кто бы не хотел туда поехать. (There is no one who wouldn\'t want to go there).

6. Imperative Alternative:
This pattern is frequently replaced by the imperative without бы to express the same timeless or hypothetical meaning (e.g., 'Кого ни спроси, никто не знает' - 'Whomever you ask, no one knows' or 'Кого ни назначь на эту должность...' - 'Whomever you appoint to this position...').