Из-за сырости в подвале книги лучше хранить не там, а в шкафу.

Из-за means because of, due to, or as a result of.

So из-за сырости means because of the dampness.

A learner may already know из-за as from behind in literal phrases like из-за дома (from behind the house), but it also has this very common figurative meaning: because of.

Examples:

• Из-за дождя мы остались дома. — We stayed home because of the rain.
• Из-за шума я не мог уснуть. — I couldn’t fall asleep because of the noise.

In this sentence, it introduces the reason why the basement is not a good place for books.

Because из-за requires the genitive case.

The base form is сырость (dampness, moisture, humidity in the unpleasant sense).
Its genitive singular form is сырости.

So:

• сырость — nominative
• из-за сырости — genitive after из-за

This is a very common pattern:

• из-за дождя
• из-за холода
• из-за проблемы

Not quite.

Сырость usually means dampness in an unpleasant, unhealthy, or mold-causing sense. It is exactly the kind of moisture that can damage books, walls, clothes, and furniture.

Влажность is more neutral and technical: humidity or moisture level.

So here сырость is the natural word, because the sentence is talking about a bad environment for storing books.

Because в with location usually takes the prepositional case.

The noun is:

• подвал — basement

In the prepositional singular:

• в подвале — in the basement

So:

• в подвале = location
• в подвал would mean motion into the basement

Compare:

• Книги лежат в подвале. — The books are in the basement.
• Мы отнесли книги в подвал. — We took the books into the basement.

Here книги is the direct object of хранить (to store / keep), so it is in the accusative plural.

For inanimate plural nouns, the accusative plural is usually the same as the nominative plural.

So:

• nominative plural: книги
• accusative plural: книги

That is why the form does not change.

Compare with an animate noun:

• я вижу студентов — I see students
  not студенты

But with inanimate nouns:

• я вижу книги — I see books

This is a very common impersonal pattern:

лучше + infinitive = it is better to ...

So:

• книги лучше хранить... = it is better to store books...

There is no explicit subject like you or one. Russian often expresses advice or general recommendations this way.

Other examples:

• Это лучше сделать сейчас. — It’s better to do this now.
• Овощи лучше хранить в холоде. — It’s better to store vegetables in the cold.

This structure sounds natural and general, not directed too strongly at one specific person.

Because the sentence is talking about general storage, not a single completed action.

Хранить is imperfective and fits ideas like:

• keeping something somewhere
• storing something over time
• general habit or recommendation

The sentence is not about putting the books somewhere once; it is about where books should be kept in general.

A perfective verb would sound wrong or would change the meaning.

Compare:

• Книги лучше хранить в шкафу. — Books are better stored in a cupboard / It’s better to keep books in a cupboard.
• Лучше положить книги в шкаф. — It’s better to put the books in the cupboard.

The second sentence is about one action of placing them there.
The original is about proper long-term storage.

Не там, а в шкафу creates a contrast:

• not there
• but in the cupboard

The word там refers back to в подвале (in the basement). Russian often does this instead of repeating the full phrase.

So the structure is:

• в подвале — first location is introduced
• не там — not there
• а в шкафу — but in the cupboard

This makes the contrast very clear and natural.

Without не там, the sentence would still be possible:

• Из-за сырости в подвале книги лучше хранить в шкафу.

But the original version is more contrastive and emphatic.

Because не ..., а ... is the normal pattern when Russian contrasts one option with another.

Here the idea is:

• not in that place
• but in this place

So а is the right conjunction.

Compare:

• не чай, а кофе — not tea, but coffee
• не там, а в шкафу — not there, but in the cupboard

Но usually means but in the sense of contradiction or concession, not direct replacement.

So:

• Он хотел уйти, но остался. — He wanted to leave, but stayed.

In this sentence, it is not a contradiction; it is a correction/replacement of one location by another. That is why а is correct.

This is a good question, because both forms exist in Russian grammar discussions, but в шкафу is the normal, natural locational form here.

Some masculine nouns can have a special prepositional form in -у / -ю when they mean location.

So:

• шкаф — cupboard / cabinet / wardrobe
• в шкафу — in the cupboard

This -у form is very common with certain nouns, especially in fixed or very natural location expressions.

Other examples:

• в лесу — in the forest
• в саду — in the garden
• на полу — on the floor
• в углу — in the corner

So in this sentence, в шкафу is the standard choice.

Там means there, and it points back to в подвале.

Russian often uses a pronoun or adverb like this instead of repeating the full noun phrase.

So the logic is:

1. mention the place: в подвале
2. refer back to it: не там
3. give the better alternative: а в шкафу

This avoids repetition and makes the sentence flow better.

In English we do the same:

• Because of the dampness in the basement, it’s better to keep books not there, but in a cupboard.

Because the sentence is a general recommendation, not advice to one specific person.

Russian very often uses impersonal constructions for this kind of statement:

• лучше хранить
• нужно сделать
• можно взять
• нельзя курить

So книги лучше хранить... means something like:

• books are best stored...
• it is better to keep books...

If you added a person, the meaning would become more specific:

• Вам лучше хранить книги в шкафу. — You’d better keep the books in a cupboard.

The original is broader and more neutral.

Yes, Russian word order is flexible, but the chosen order sounds natural and helps the sentence’s logic.

Current order:

• Из-за сырости в подвале — reason + place
• книги лучше хранить — main statement
• не там, а в шкафу — contrast between locations

This order works well because it first gives the problem, then the recommendation, then the correction of location.

You could rearrange parts, but the emphasis would change. For example:

• Книги лучше хранить не в подвале, а в шкафу из-за сырости.
  This is understandable, but less natural in tone and information flow.

The original sounds smooth and idiomatic.

Because а is a coordinating conjunction, and in this contrast pattern Russian normally uses a comma before it.

So:

• не там, а в шкафу

This is the standard punctuation for:

• не X, а Y

Examples:

• Не сегодня, а завтра.
• Не в городе, а в деревне.
• Не там, а здесь.

The comma marks the contrast clearly.