сколько бы ни

The сколько бы ни construction is an advanced way to express universal concession regarding quantity.

1. Morphology and Syntax:

• Declension and Genitive Case: The word сколько declines to match the required case. When used in the nominative or accusative to mean 'how much/many of something', the noun that follows must be in the Genitive case (e.g., Сколько бы денег ни было... - No matter how much money there might be...). In oblique cases, it takes the same case as the noun, as both are governed by the preposition or verb (e.g., со сколькими бы людьми ни говорил... - No matter how many people he might talk to...).
• Prepositions: Prepositions always precede сколько (e.g., со сколькими бы...). Do not confuse this with Russian negative pronouns where the preposition splits the word (e.g., ни с кем).
• Adverbial Use: Сколько frequently acts as an adverb modifying the verb directly to mean 'how much' or 'how long' (e.g., Сколько бы он ни спал... - No matter how much he might sleep...).
• Verb Form: Because of the particle бы, the verb typically takes the past tense form to create the subjunctive (or conditional) mood. While this often refers to present or future hypotheticals, it can also describe generalized or repeated actual past events (e.g., Сколько бы он ни спал, он чувствовал себя усталым - No matter how much he slept, he felt tired). An infinitive can also be used (e.g., Сколько бы ни смотреть на море... - No matter how much one looks at the sea...).
• Verbal Aspect: Both aspects can be used, but they carry different nuances. Imperfective verbs emphasize duration or repeated attempts (e.g., Сколько бы я ни старался... - No matter how much I might try), while perfective verbs emphasize a hypothetical completed result (e.g., Сколько бы слов я ни выучил... - No matter how many words I manage to learn).
• Particle Placement: Бы usually follows сколько immediately. The particle ни typically stands before the verb, and subjects, adverbs, or the noun being quantified often intervene between сколько бы and ни (e.g., Сколько бы я ни старался... - No matter how much I might try...; Сколько бы денег ни было... - No matter how much money there might be...).
• Main Clause Pairing: The main clause uses the indicative mood (present, past, or future) to show the actual, unchanging result, contrasting with the subjunctive mood in the subordinate clause. It frequently uses words like всё равно (still / anyway) or всё-таки (nevertheless) to emphasize this.
• Spelling: The particles бы and ни are always written as separate words, never attached to сколько with hyphens.
• Punctuation: As a concessive subordinate clause, it must always be separated from the main clause by a comma.

2. The Role of 'Ни':
It is crucial to use ни, not не. In Russian, ни acts as a particle of totality in these constructions, reinforcing that any amount, no matter how large, will not change the result. Using не would incorrectly turn the clause into a negative one. For example, сколько он не спал means 'how much he didn't sleep', whereas сколько бы он ни спал means 'no matter how much he sleeps'. However, be aware that you will frequently encounter the incorrect form сколько бы не in informal writing on the internet, as this is a very common mistake made by native speakers.

3. Nuance vs. 'Сколько ни':
While сколько ни is often used for factual events and can take various indicative tenses (past, present, or future) or the imperative mood (e.g., Сколько ни старайся...), the addition of бы requires either the past tense or an infinitive, making the statement more general, hypothetical, or focused on future potential ('No matter how much I might try, I will fail').