GrammarDemonstrative

A demonstrative pronoun is a pointing word: this book, that house, such a person, so much money. The ones you need are:

э́то (this is, that is) - fixed form

• Э́то моя́ сестра́. (This is my sister.)
• Э́то мои́ друзья́. (These are my friends.)

э́тот (this / these) - something relatively close or currently being discussed.

• э́тот дом (this house)
• э́та кни́га (this book)

тот (that / those) - something more distant, previously mentioned, or contrasted with another thing.

• тот дом (that house)
• то ме́сто (that place)

тако́й (such/so)

• Я хочу́ тако́й телефо́н. (I want a phone like this.)
• Мы не зна́ем таки́х люде́й ( We do not know such people.)

тако́в (the short, predicative form of тако́й: "such is …")

• Тако́в наш план. (Such is our plan.)
• Такова́ жизнь. (Such is life.)

сто́лько (so much/so many)

• Здесь сто́лько люде́й. (There are so many people here.)
• У меня́ нет сто́лько вре́мени. (I do not have that much time.)

Near and far: э́тот vs тот

Russian splits "this" and "that" similar to English. э́тот points to what is near (in space, time or attention); тот points to what is farther away or to "the other one":

• Э́тот дом но́вый, а тот дом ста́рый. (This house is new, and that house is old.)
• Возьми́ не э́ту ру́чку, а ту. (Take not this pen, but that one.)

тот also has the bookish sense "the former" and appears in fixed phrases such as в то вре́мя (at that time) and на той неде́ле (last week).

Declension of э́тот

In the nominative the four base forms are э́тот, э́та, э́то and э́ти:

Just as with adjectives and nouns, the accusative watches animacy: for masculine or plural the accusative copies the nominative for inanimate and the genitive for animate:

• Я чита́ю э́тот журна́л. (I am reading this magazine — inanimate → like nominative.)
• Я зна́ю э́того челове́ка. (I know this person — animate → like genitive.)
• Я ви́жу э́тих студе́нтов. (I see these students — animate plural → like genitive.)

Declension of тот

The nominative forms are тот, та, то, те. The endings look like э́тот's, but several are stressed and the plural switches to the soft -е- vowel (тем, те́ми, тех):

Note the genitive -г- that is spelt but pronounced [v], exactly as in его́: того́ sounds like "tavó". And take care with the instrumental: masculine/neuter тем, feminine той, plural те́ми.

The invariable э́то

Russian uses э́то in two completely different ways:

1. э́то as "this is / that is / these are"

When you name or identify something ("This is …", "That is …", "These are …"), э́то is a fixed, unchanging word. It does not agree with anything, it always stays э́то no matter of what follows:

• Э́то мой дом. (This is my house — дом is masculine, still э́то.)
• Э́то моя́ маши́на. (This is my car — маши́на is feminine, still э́то.)
• Э́то кни́ги. (These are books — plural, still э́то.)
• Э́то Ива́н и Мари́я. (This is Ivan and Maria.)

2. э́тот / э́та / э́то / э́ти as modifier "this ___"

When the word sits in front of a noun and means "this ___", it is the ordinary demonstrative and must agree with that noun:

• Э́тот дом мой. (This house is mine.)
• Э́та маши́на моя́. (This car is mine.)
• Э́то окно́ моё. (This window is mine — окно́ is neuter, so the modifier is э́то too.)
• Э́ти кни́ги мои́. (These books are mine.)

Compare the two uses side by side:

Quick test: if you can put "is/are" after the pointing word in English ("This is …"), use fixed э́то. If the pointing word leans on a following noun ("this house"), make it agree: э́тот / э́та / э́то / э́ти.

тако́й — "such / so"

тако́й means "such (a)" or "so" before an adjective or noun, and it declines exactly like a hard adjective (тако́й, така́я, тако́е, таки́е):

• Он тако́й у́мный! (He is so smart!)
• Э́то така́я краси́вая пе́сня! (This is such a beautiful song!)
• Я никогда́ не ви́дел таки́х люде́й. (I have never seen such people.)

тако́й vs так

Do not confuse тако́й with the adverb так. Use тако́й (agreeing) before an adjective + noun or a bare adjective; use так (invariable) before a verb or an adverb:

• Она́ така́я краси́вая. (She is so beautiful.) — before an adjective → тако́й
• Она́ так краси́во поёт. (She sings so beautifully.) — before an adverb → так
• Я так уста́л. (I am so tired.) — with a verb form → так

тако́в — the short, predicative form

тако́в is the short (predicative) form of тако́й. It never stands before a noun and never takes a case ending. It appears only as the predicate ("… is such / is like that"), agreeing with the subject in gender and number only:

тако́в is noticeably bookish — you will meet it mostly in the set phrase Такова́ жизнь (Such is life.) and in formal writing.

• Такова́ жизнь. (Such is life.)
• Таковы́ пра́вила. (Such are the rules.)
• Его́ отве́т был тако́в: … (His answer was as follows: …)
• Усло́вия таковы́, что на́до спеши́ть. (The conditions are such that we must hurry.)

Compare the two forms: the full тако́й modifies a noun and declines (Э́то тако́й вопро́с — "This is such a question"), while the short тако́в only predicates and never changes for case (Вопро́с тако́в — "The question is such / is like that").

сто́лько — "so much / so many"

сто́лько is a quantity word, and like other quantity words (мно́го, ма́ло, ско́лько) it takes the genitive of whatever is counted — genitive singular for uncountable things, genitive plural for countable ones:

• сто́лько книг (so many books — genitive plural)
• сто́лько вре́мени (so much time — genitive singular)

In the nominative and accusative it stays сто́лько; in the other cases it agrees with its noun like a plural adjective (сто́льких, сто́льким, сто́лькими), but these forms are rare. Its question-word partner is ско́лько (how much / how many) — see the interrogative and relative pronouns.

Useful combinations

• тот же (са́мый) (the same) — Мы живём в том же до́ме. (We live in the same house.)
• тот, кото́рый… (the one that / which…) — Э́то тот дом, кото́рый я купи́л. (This is the house that I bought.).
• э́то всё (that is all)
• и всё э́то (and all this)
• по́сле э́того (after this)
• кро́ме того́ (besides that)

Common mistakes

• Making э́то agree when it should stay fixed. In "This is …" it never changes.
  Э́та моя квартира (wrong) → Э́то моя квартира (correct)
• Leaving э́тот unchanged when it modifies a noun. Before a noun it must agree.
  Э́то маши́на моя́ (means "This is my car", not "This car is mine") → Э́та маши́на моя́ (This car is mine)
• Using так where тако́й is needed (or the reverse). так goes with verbs and adverbs, тако́й with adjectives and nouns.
  Она́ так краси́вая (wrong) → Она́ така́я краси́вая (correct)
• Forgetting the genitive after сто́лько.
  сто́лько кни́ги (wrong) → сто́лько книг (correct)
• Ignoring animacy in the accusative.
  Я зна́ю э́тот челове́к (wrong) → Я зна́ю э́того челове́ка (correct)

Summary

• э́тот = "this" (near); тот = "that" (far / the other).
• Both agree with their noun in gender, number and case; the accusative watches animacy (э́того челове́ка).
• Fixed э́то = "this is / these are" and never changes; the modifier э́тот / э́та / э́то / э́ти agrees.
• тако́й ("such, so") agrees like an adjective; так ("so") is an invariable adverb.
• сто́лько ("so much / many") takes the genitive: сто́лько книг.
• Handy fixed phrases: тот же (the same), тот, кото́рый (the one that), в то вре́мя (at that time).