сколько

The word сколько is essential for daily life in Russia, covering everything from shopping to asking someone's age. Note that the stress always falls on the first syllable. You will frequently hear native speakers make the colloquial mistake of inventing a non-existent ending and shifting the stress to it, saying things like до скольки or ко скольки. The correct standard forms are до скольких (Genitive) and ко скольким (Dative), with the stress remaining on the first syllable.

1. Case Government:
When сколько is in the nominative or inanimate accusative, it acts as a quantifier. This means the noun (and any modifying adjectives) following it must change:

• Countable nouns: Use the Genitive Plural for both the noun and adjectives. Example: Сколько новых книг? (How many new books?)
• Uncountable nouns: Use the Genitive Singular for both the noun and adjectives. Example: Сколько холодной воды? (How much cold water?)
• Plural-only nouns: Words like деньги (money) or очки (glasses) take the Genitive Plural. Example: Сколько денег? (How much money?)

2. Oblique Cases and Animate Accusative:
In other cases (Dative, Instrumental, Prepositional), сколько declines like a plural adjective (скольких, скольким, сколькими). Crucially, the noun drops the Genitive Plural and takes the required oblique case in the plural alongside сколько. For example: со сколькими студентами (Instrumental plural for both) or о скольких книгах (Prepositional plural for both). For animate nouns in the Accusative, you can decline it (Скольких студентов ты видел?), but in modern Russian, it is extremely common and perfectly correct to just use the base form with the Genitive Plural (Сколько студентов ты видел?).

3. Modifying Verbs:
Сколько can also act as an adverb modifying a verb directly, meaning 'how much' or 'how long', without any noun attached. Example: Сколько ты спал? (How long did you sleep?)

4. Common Phrases:

• Price: Сколько это стоит? (How much does this cost?)
• Age: Сколько тебе лет? (How old are you?)
• Time: Сколько времени? (What time is it?)

5. Verb Agreement:
When сколько is the subject in the past tense, the verb often takes the neuter singular form (ending in -о), such as было. Plural agreement is also acceptable, especially for people (e.g., Сколько человек пришли?).