Learn Hardcore Russian: В школе у меня был старший одноклассник, который помогал мне с математикой. - At school I had an older classmate who helped me with math.

Why does the sentence use у меня был старший одноклассник instead of something like я имел старшего одноклассника to say “I had an older classmate”?

In Russian, the normal, natural way to say “I have / I had something” is with the у + Genitive + есть/был construction:

У меня есть друг. – I have a friend.
У меня был друг. – I had a friend.

Literally this is closer to “At me there is/was a friend.”

Using иметь (“to have”) with people (я имел друга) usually sounds bookish, stiff, or even a bit wrong in everyday speech, especially when talking about relationships (friends, classmates, family). The иметь verb is more common in formal, technical, or idiomatic contexts.

So В школе у меня был старший одноклассник is the natural Russian way to express “At school I had an older classmate.”

Why is it в школе, with школе in that form, and not в школа?

В школе uses the prepositional case after the preposition в to express location (“in/at school”).

Nominative: школа (school – as a dictionary form)
Prepositional (about / in / at school): в школе

When you talk about being in a place (not direction into), Russian usually uses:

в + prepositional (in, at)
- в школе – at school
- в городе – in the city
на + prepositional (on, at certain places)
- на работе – at work
- на улице – outside / in the street

So в школа is ungrammatical; the noun has to be put into the prepositional case: в школе.

What exactly does старший одноклассник mean? Is he just “older”, or higher grade, or what?

Одноклассник means “classmate” – literally “someone who is in the same class (класс) as you.”

Старший means “older,” “senior,” or “higher” in some hierarchy. In this particular combination:

старший одноклассник usually means:
- A classmate who is older in age than you (for example, he repeated a year and is older than the rest),
- or a classmate who is in a higher grade but is closely connected to your class (for example, in some contexts people mix class/grade terms).

But in many contexts, Russian speakers simply mean “an older classmate (than me)” – someone who is both your peer at school but older, or a “senior” you knew closely in school.

If the person were definitely not in your class but just in a higher grade, people would more often say something like старший ученик or ученик из старших классов (“a student from the upper grades”). The presence of одноклассник suggests “same class” + older by age.

What case is старший одноклассник in, and what is its grammatical role in the sentence?

Старший одноклассник is in the nominative singular masculine:

старший – nominative masculine singular adjective
одноклассник – nominative masculine singular noun

It is the subject of the verb был in the existential construction у меня был старший одноклассник:

Literally: “At me there was an older classmate.”
Grammatically:
- у меня – “at me” (Genitive; an “owner” phrase)
- был – “was”
- старший одноклассник – the thing that “was” (subject)

So the subject of был is старший одноклассник.

Why does the sentence use который and not кто for “who helped me with math”?

Который is a relative pronoun, like English who/which/that in relative clauses (who helped me, which I bought, etc.).

You use который to connect a noun to a clause that describes it:

одноклассник, который помогал мне
“the classmate who helped me”

Кто usually introduces a separate clause (“who?” as a question, or “whoever”):

Кто помогал мне с математикой? – Who helped me with math?
Кто помогал мне, тот молодец. – Whoever helped me is great.

In a sentence like ours, where “who” refers back to одноклассник as a description of that noun, Russian needs который, not кто:

✅ одноклассник, который помогал мне…
❌ одноклассник, кто помогал мне… (sounds wrong/foreign)

Why is there a comma before который?

The phrase который помогал мне с математикой is a relative clause that gives extra information about одноклассник.

In Russian, relative clauses introduced by который, кто, что, etc. are normally separated from the main clause by commas:

…одноклассник, который помогал мне…
…человек, который живёт рядом… – the person who lives next door

So the comma before который is required by standard Russian punctuation rules.

Why is который in this exact form and not something like которого or которому?

Который must agree with одноклассник (the noun it refers to) in:

Gender: masculine (одноклассник – masc.)
Number: singular
Case: determined by its role inside the relative clause

Inside the clause который помогал мне с математикой:

который is the subject of помогал
- “who helped me” → who = subject
The subject in Russian takes the nominative case.

So we get:

masculine, singular, nominative: который

If it were an object, we would have a different case, e.g.:

одноклассник, которого я часто видел – “…a classmate whom I often saw” (Genitive/Accusative которого as the object of “saw”).

Why is it помогал мне, with мне and not меня?

The verb помогать (imperfective) / помочь (perfective) takes:

Dative for the person you help: кому?
Instrumental (often with с) or prepositional в чём? for the thing you help with.

Here:

помогал – “(he) was helping / used to help”
кому? – мне (Dative “to me”)
с чем? – с математикой (Instrumental “with math”)

So:

Он помогал мне с математикой. – He helped me with math.

If you used меня (Accusative/Genitive), it would be ungrammatical with помогать, because помогать simply doesn’t govern the Accusative for the person being helped. It always uses the Dative: мне, тебе, ему, ей, нам, вам, им.

Why is it с математикой and not something like по математике or в математике?

All of these can appear with verbs of helping, but they have slightly different flavors.

With помогать, the most natural way to express “help with a subject/topic” is:

помогать кому с чем
- Он помогал мне с математикой. – He helped me with math.

Here с + инструментальный (математикой) indicates the area/topic where you needed help.

Alternatives:

помогать кому в чём
- Он помогал мне в математике. – also possible; “helped me in math” (sounds slightly more formal or “abstract-ability” oriented).
по математике is often used with other verbs:
- заниматься по математике – to study/practice math
- учебник по математике – a textbook on math

So с математикой is the most straightforward and idiomatic choice with помогал here.

What does the form помогал tell us, and how is it different from помог?

Both are past tense of the verb “to help,” but they belong to different aspects:

помогал – past, masculine singular, imperfective (from помогать)
помог – past, masculine singular, perfective (from помочь)

Differences:

помогал suggests:
- repeated or habitual action: “used to help,” “would help,”
- or a process/duration in the past.
- In this sentence, it very naturally means “he used to help me with math (more than once / regularly).”
помог suggests:
- a single, completed action: “helped (once, and that’s it).”
- …одноклассник, который помог мне с математикой would normally sound like he helped you at one particular time.

Since we are talking about school and a recurring situation, помогал is the natural choice to convey repeated help over time.

Can the word order be changed, for example to У меня в школе был старший одноклассник, который…? Does it change the meaning?

Yes, Russian word order is quite flexible here, and some variations are possible:

В школе у меня был старший одноклассник, который помогал мне с математикой.
– Neutral, focusing slightly on the setting (“At school, I had…”).
У меня в школе был старший одноклассник, который помогал мне с математикой.
– Very natural too; emphasizes a bit more that I, at school, had such a classmate.
У меня был в школе старший одноклассник, который…
– Also possible, a different rhythmic emphasis, but still correct.

The basic meaning doesn’t change: you’re talking about a period when you were at school and you had an older classmate who helped you with math. The differences are mostly in nuance and emphasis, not in core meaning.

Does this sentence imply that there was only one older classmate who helped me, or could there have been several?

Grammatically, старший одноклассник is singular, so literally it talks about one older classmate.

However, Russian (like English) can sometimes use the singular in a somewhat looser, storytelling way, without strongly excluding the possibility of others. Context would clarify whether you mean:

literally one specific classmate, or
effectively “there was this one (not necessarily the only one) older classmate who helped me with math.”

If you wanted to clearly say there were several, you’d use the plural:

У меня были старшие одноклассники, которые помогали мне с математикой.
– I had older classmates who helped me with math.