что + Complement Clause

The pattern что + придаточное изъяснительное is the standard way to form object or explanatory clauses in Russian, typically used for reported speech, thoughts, and facts.

1. Usage and Meaning
It is used to report declarative statements, regardless of whether the information is a fact or not (e.g., Он солгал, что... - He lied that...). It typically follows:

• Verbs of Speech: сказать (to say), отвечать (to answer).
• Verbs of Thought: думать (to think), знать (to know), понимать (to understand).
• Verbs of Perception: видеть (to see), слышать (to hear), чувствовать (to feel). Note: with verbs of perception, как is often preferred over что to emphasize the process or immediate observation (e.g., Я видел, как он ушёл).
• Verbs of Emotion: радоваться (to be glad).
• Nouns: факт (fact), мысль (thought), известие (news).

2. Structural Rules

• The Comma: In Russian, you generally place a comma before что when it introduces a new clause, though there are exceptions (such as within compound conjunctions like потому что, which introduces an adverbial clause of reason rather than an explanatory clause, or in certain fixed expressions).
• Omission: In spoken Russian and informal writing, the conjunction что (meaning 'that') is frequently and naturally omitted, creating an asyndetic compound sentence. In formal written Russian, however, it is generally required. When omitted in writing, formal punctuation rules prescribe a dash (тире) if the main verb is neutral and unstressed (e.g., Я думаю — он прав - I think he is right), though a comma is extremely common and widely accepted in modern writing for short sentences (Я думаю, он прав). If the main verb is stressed or followed by a slight pause, a colon is used instead (e.g., Я знаю: он прав - I know he is right). Note that this omission rule only applies when что functions as a conjunction; the relative pronoun что (meaning 'what') cannot be omitted.
• Word Order: While the что clause typically follows the main clause, it can easily precede it for stylistic emphasis (e.g., Что он прав, я знал давно - That he is right, I knew long ago).
• Pronunciation: Although written with 'ч', it is almost always pronounced as [што].

3. Tense Consistency
Russian does not 'backshift' tenses in reported speech like English does. If the original thought was in the present tense, it stays in the present tense even if the main verb is in the past.
Example: Он сказал, что работает (He said that he was working — literally: 'He said that he is working').

4. Correlative 'то'
The pronoun то (in the appropriate case) is often used when the main verb or adjective requires a preposition or an oblique case (Genitive, Dative, Instrumental, or Prepositional) to connect to the clause. A crucial rule is that a Russian preposition cannot directly govern the conjunction что. Therefore, if you drop то, you MUST also drop the preposition (e.g., saying на что он прав is strictly incorrect). While dropping both the preposition and то is acceptable with some words (for example, with the adjective рад, the correlative тому is optional: Я рад, что вы пришли), it is strictly required and cannot be dropped with others. For example, with настаивать на, you must say Он настаивал на том, что он прав. Similarly, with начаться с, you must say Всё началось с того, что.... Note that the comma must be placed after the correlative word and immediately before что (e.g., Дело в том, что...).

5. Statements vs. Questions and Commands
Note that что is used only for declarative statements. To report a question, you must use ли or a specific question word like где or почему instead of что. Additionally, to report commands, requests, or desires, you must use чтобы rather than что (e.g., Она сказала, чтобы он ушёл - She told him to leave).

6. 'Что' as a Relative Pronoun
Besides acting as a simple conjunction ('that'), что can also function as a relative pronoun meaning 'what' in reported speech. In this case, it acts as a core component (like the subject or object) of the subordinate clause, and crucially, it declines for case depending on its role in that clause (чего, чему, чем, о чём). Example: Я не знаю, что он делает (I don't know what he is doing) or Она спросила, о чём мы говорим (She asked what we were talking about).