Если объём сумки маленький, туда не поместятся ни ноутбук, ни тетради.

Объём сумки literally means the volume/capacity of the bag.

Russian often uses this pattern:

• [noun] + genitive = the [noun] of ...
• объём сумки = the bag’s capacity
• цвет машины = the color of the car
• ручка двери = the handle of the door

So сумки is genitive singular because it depends on объём.

Because маленький agrees with объём, not with сумка.

• объём is masculine singular
• so the adjective must also be masculine singular: маленький

If the sentence were about the bag itself, you could say:

• Если сумка маленькая... = If the bag is small...

But here the idea is specifically the bag’s capacity is small, not just its physical size.

Туда means there / into that place.

In this sentence, it refers to the bag:
туда не поместятся... = they won’t fit in there

Russian often uses туда when the destination is already understood from context. It sounds natural and avoids repeating в сумку.

So these are all possible ideas:

• туда не поместятся = won’t fit in there
• в сумку не поместятся = won’t fit into the bag
• в неё не поместятся = won’t fit into it

All are possible, but туда is very natural.

Because Если объём сумки маленький is a subordinate clause introduced by если (if).

Russian normally separates this kind of clause with a comma:

• Если ..., ...
• ..., если ...

So:

• Если объём сумки маленький, туда не поместятся ни ноутбук, ни тетради.

This is the standard punctuation rule.

Поместятся comes from поместиться, which means:

• to fit
• to be accommodated
• to have enough room to go in

So:

• не поместятся = will not fit

It is a very common verb when talking about whether something can go inside a container, room, car, bag, etc.

Examples:

• Книги не поместятся в коробку. = The books won’t fit in the box.
• Все гости не поместятся в комнате. = Not all the guests will fit in the room.

Because the subject is effectively ни ноутбук, ни тетради.

That means:

• neither the laptop nor the notebooks

Since more than one thing is being discussed together, Russian uses the plural verb:

• не поместятся = will not fit

If there were only one item, it would be singular:

• Ноутбук туда не поместится. = The laptop won’t fit in there.

In Russian, the structure ни ..., ни ... is the normal way to say neither ... nor ....

So:

• ни ноутбук, ни тетради = neither the laptop nor the notebooks

It usually appears together with a negative verb:

• не поместятся ни ноутбук, ни тетради

This is the standard Russian negative pattern.
Using не ноутбук и не тетради here would sound unnatural.

Because they are the things that won’t fit — in other words, they function as the grammatical subject of the verb поместятся.

So we get nominative forms:

• ноутбук = nominative singular
• тетради = nominative plural

Even though the sentence is negative, these nouns are still the subject, not the object.

Compare:

• Ноутбук не поместится. = The laptop won’t fit.
• Тетради не поместятся. = The notebooks won’t fit.

Because the sentence is talking about:

• one laptop
• multiple notebooks

Russian simply uses whatever number matches the meaning.

So:

• ни ноутбук = not even a laptop / neither a laptop
• ни тетради = nor notebooks

There is nothing unusual grammatically here; it just reflects the real-world quantities being mentioned.

Yes, absolutely.

You could say:

• ...в неё не поместятся ни ноутбук, ни тетради.

That means won’t fit into it, with неё referring to сумка.

The difference is mainly stylistic:

• туда = in there / into there, a bit more general
• в неё = directly points back to the bag

Both are correct.

Russian often uses the present tense after если when talking about a general condition:

• Если объём сумки маленький... = If the bag’s capacity is small...

Then the main clause can describe the result:

• ...туда не поместятся... = ...they won’t fit there.

This is very normal in Russian. The idea is not a specific future event only, but a general condition-and-result relationship.

It is correct, but it is a bit more specific and slightly more formal than simply saying the bag is small.

It focuses on capacity:

• объём сумки маленький = the bag’s capacity is small

A more everyday version might be:

• Если сумка маленькая, туда не поместятся ни ноутбук, ни тетради.

That means roughly the same thing, but it sounds simpler and more conversational.

So the original sentence is fine; it just emphasizes capacity/space inside.

Yes. Russian word order is flexible, though the emphasis changes.

Original:

• Если объём сумки маленький, туда не поместятся ни ноутбук, ни тетради.

Possible variations:

• Если объём сумки маленький, ни ноутбук, ни тетради туда не поместятся.
• Ни ноутбук, ни тетради туда не поместятся, если объём сумки маленький.

All of these are grammatical. The original version sounds natural and neutral.

In Russian, ни ... ни ... usually does not replace the main negation. The verb still normally stays negative.

So the standard pattern is:

• не
  • verb + ни ..., ни ...

Example:

• туда не поместятся ни ноутбук, ни тетради

This is one of those places where Russian uses what looks like “double negation,” but it is actually the normal grammar.

So you should think of it as a fixed pattern:

• не вижу ни маму, ни папу = I see neither mom nor dad
• не пришли ни брат, ни сестра = Neither brother nor sister came

Mostly, yes. It usually means to fit into a space or to be contained.

Common uses:

• objects fitting into a bag, box, car, room
• people fitting into a room, elevator, taxi
• sometimes abstract things, like text fitting on a page

Examples:

• Это не поместится в чемодан. = This won’t fit in the suitcase.
• Все не поместятся в лифт. = Not everyone will fit in the elevator.

So in your sentence, it is very literally about available space in the bag.