Learn Hardcore Russian: Новая грамматическая тема: неопределённые местоимения с суффиксом «-то» (кто‑то, что‑то, где‑то и так далее). - New grammar topic: indefinite pronouns with the suffix “-то” кто‑то, что‑то, где‑то, and so on.

тема (topic) is a feminine noun.
Adjectives in Russian agree with the noun in gender, number, and case.
So we get:
- новая тема – new topic (feminine)
- новый урок – new lesson (masculine)
- новое правило – new rule (neuter)

Here, Новая грамматическая тема is a noun phrase in the nominative: “(This is a) new grammar topic.”

Why is it грамматическая тема and not грамматическая грамматика or something similar?

In Russian, тема means “topic”, so грамматическая тема literally means “grammar topic” / “grammatical topic”.

грамматика = grammar (the subject)
тема = topic
грамматическая тема = a topic that belongs to the area of grammar

Using грамматическая грамматика would not make sense; it would be like saying “grammatical grammar.” You need a noun for “topic” (тема), and the adjective грамматическая describes what kind of topic it is.

Why is грамматическая also feminine and in the same form as новая?

Both новая and грамматическая describe the same noun тема.

тема – feminine, singular, nominative.
Therefore, both adjectives must match that:
- новая (new) – fem. sg. nom.
- грамматическая (grammatical) – fem. sg. nom.

In Russian you can have several adjectives in a row, all agreeing with the same noun:

новая интересная книга – a new interesting book
большой старый дом – a big old house

Here: Новая грамматическая тема – a new grammar topic.

Why is there a colon after Новая грамматическая тема?

In Russian, a colon is often used:

Before an explanation or definition
Before a list that elaborates on what was just mentioned

Here, Новая грамматическая тема is followed by an explanation of what that topic is:

неопределённые местоимения с суффиксом -то …

So the structure is like:

New grammar topic: indefinite pronouns with the suffix -то …

This is a standard, correct use of the colon in Russian.

Why is неопределённые местоимения in the plural? We are talking about one topic, right?

Yes, the topic is singular (тема), but the thing the topic is about is plural.

тема – the topic (singular)
The topic concerns a group / class of words: неопределённые местоимения – indefinite pronouns (plural).

So:

Новая грамматическая тема – one new topic
That topic is: неопределённые местоимения – a set of many pronouns (кто‑то, что‑то, где‑то, …)

Therefore, неопределённые and местоимения are both plural, nominative.

What does неопределённые literally mean, and why does it have ё?

Literally, неопределённые means “indefinite, not defined, not specific”.

не- = not
определённый = definite, specific
неопределённый = indefinite
неопределённые = plural form (indefinite, as a group)

The ё shows the stressed syllable: не-о-преде-ЛЁН-ны-е.

In everyday writing, Russians often omit the dots and write неопределенные, but the correct, fully marked form is with ё. The pronunciation stays the same.

What case is суффиксом in, and why is that case used?

суффиксом is in the instrumental case, singular.

The preposition с (with) usually takes the instrumental:

с чем? – with what?
с другом – with a (male) friend
с книгой – with a book
с суффиксом – with a suffix

So с суффиксом -то = with the suffix -то.

Why is it с суффиксом -то and not something like суффикс -то without с?

Both patterns are possible in Russian, but they have slightly different focuses.

суффикс -то – “the suffix -то” (just naming the suffix)
местоимения с суффиксом -то – “pronouns with the suffix -то”

In this sentence, с суффиксом -то functions as a description of what kind of pronouns they are: pronouns that have / take this suffix. Using с emphasizes that -то is attached to those pronouns.

Why are кто‑то, что‑то, где‑то written with a hyphen?

In Russian, many indefinite pronouns and adverbs are formed by adding short particles like -то, -нибудь, -либо etc. These are always written with a hyphen:

кто‑то – someone
что‑то – something
где‑то – somewhere
когда‑то – sometime
кто‑нибудь, что‑нибудь – someone, something (more “any-”/“ever”‑like)
кто‑либо, что‑либо – someone, something (formal / written style)

The hyphen shows that this is one word (a pronoun or adverb) made from a base word (кто, что, где) plus an attached particle (-то).

What exactly is -то here? Is it a suffix, a particle, or something else?

In school grammar, it is often called a суффикс in this specific construction, but more precisely it is a particle that is written as if it were a suffix.

It cannot stand alone: you can’t say *то in this meaning by itself.
It attaches to pronouns and adverbs: кто‑то, что‑то, где‑то.
It adds the meaning of “some, some kind of, some unspecified”.

So:

From a meaning / syntax point of view: it’s a particle.
From an orthography (spelling) point of view: it is written like a suffix with a hyphen, which is why the teacher calls it суффикс -то.

Are кто‑то, что‑то, где‑то in a particular case here?

They are given in their dictionary (basic) forms, which are:

кто‑то – nominative singular (who? someone)
что‑то – nominative singular (what? something)
где‑то – adverb (where? somewhere, place adverb; it doesn’t decline)

Since they are just examples in brackets, not used in a sentence of their own, they appear in their default forms.

Do pronouns like кто‑то and что‑то change by case?

Yes. The -то part stays, but the main pronoun changes by case. For example:

кто‑то (someone):

Nom.: кто‑то – someone
Gen.: кого‑то – of someone / someone’s
Dat.: кому‑то – to someone
Acc.: кого‑то – someone (object)
Instr.: кем‑то – with/by someone
Prep.: о ком‑то – about someone

что‑то (something):

Nom.: что‑то – something
Gen.: чего‑то
Dat.: чему‑то
Acc.: что‑то
Instr.: чем‑то
Prep.: о чём‑то

You always attach -то to the correct case form of the pronoun.

What is the difference between pronouns with -то (like кто‑то) and with -нибудь (like кто‑нибудь)?

Both are indefinite, but their usage and nuance differ:

-то
- Usually refers to some specific but unknown person/thing.
- Often used when the speaker has somebody / something definite in mind, but doesn’t (or can’t) say who/what.
- Example idea: “Someone (in particular, but I won’t say who) called you.”
-нибудь
- More like “any, any at all, random”.
- Often used in questions, negations, and when the identity really doesn’t matter.
- Example idea: “Call any doctor”, “Do you know any good café?”

In this lesson, the focus is on the -то type: неопределённые местоимения с суффиксом -то.

Why is и так далее used instead of и т.д.?

Both exist and mean “and so on / etc.”:

и так далее – full phrase, neutral, used in speech and writing.
и т.д. – abbreviation, mainly in more informal or technical writing, notes, etc.

In a textbook explanation or a clear sentence for learners, it is more natural to write the full form и так далее to avoid extra abbreviations.

Why is тема singular when the topic seems to include many different pronouns?

Because тема names the category / subject area, and a category is treated as one topic:

Тема урока: прошедшее время. – The topic of the lesson: the past tense.
Новая тема: глаголы движения. – New topic: verbs of motion.
Новая грамматическая тема: неопределённые местоимения с суффиксом -то.

Even though неопределённые местоимения includes many individual words, together they form one grammar topic, so тема is correctly singular.