Не то чтобы дети часто ругаются, но из‑за кубиков и маленькой машинки иногда всё же спорят.

Не то чтобы is an idiomatic softening phrase. In this sentence, it means something like:

• It’s not that...
• Not exactly that...
• I wouldn’t say that...

So Не то чтобы дети часто ругаются does not mean a blunt The children don’t often quarrel. It sounds softer and more nuanced, like:

• It’s not that the children quarrel often, but...
• I wouldn’t say the children quarrel often, but...

This construction often introduces a contrast: not really X, but still Y.

Because the sentence has two clauses joined by но (but):

• Не то чтобы дети часто ругаются
• но из‑за кубиков и маленькой машинки иногда всё же спорят

Russian normally uses a comma before но, just like English often uses a comma before but in longer sentences.

Also, the first part with Не то чтобы... is a complete idea, so the comma helps separate it from the contrasting second part.

They are close, but not identical.

• ругаться = to quarrel, argue angrily, use harsh words, sometimes even to scold
• спорить = to argue, dispute, disagree

In this sentence:

• дети часто ругаются suggests more serious or emotionally heated quarrelling
• иногда всё же спорят sounds milder: they do still argue/dispute sometimes

So the sentence creates a contrast:

• they are not often openly quarrelling
• but they do sometimes argue over the toys

In Russian, the present tense is often used for habitual or general repeated actions, just as in English:

• Children often argue
• They sometimes quarrel

So here the present tense does not mean only right now. It means this happens from time to time in general.

Both verbs are imperfective, which fits repeated or ongoing behavior:

• ругаются
• спорят

Because из‑за requires the genitive case.

So:

• кубики → кубиков
• маленькая машинка → маленькой машинки

That is why both the noun and adjective change form.

Here из‑за means because of, due to, or in this context more naturally over:

• из‑за кубиков = over the blocks
• из‑за маленькой машинки = over the little toy car

Not always. Из‑за has two main meanings:

1. from behind

   • из‑за дома = from behind the house

2. because of / due to / over

   • из‑за дождя = because of the rain
   • из‑за игрушек = over the toys

In your sentence, it clearly has the second meaning: the children argue because of / over the blocks and the little car.

Кубики literally means cubes, but in everyday contexts it often means toy blocks or building blocks.

So in this sentence, из‑за кубиков most naturally means:

• over the blocks
• over the toy blocks

The form кубиков is the genitive plural, required by из‑за.

Because after из‑за, you need the genitive, not the accusative.

Compare:

• nominative: маленькая машинка
• accusative: маленькую машинку
• genitive: маленькой машинки

Since the sentence has из‑за, the correct form is:

• из‑за маленькой машинки

Also, машинка is a diminutive form, so it often means little car, toy car, or just a more affectionate version of машина.

Всё же means something like:

• still
• all the same
• nevertheless

It adds a slight feeling of concession:

• they do not often quarrel,
• but they still sometimes argue

So иногда всё же спорят is stronger and more natural than just иногда спорят. It emphasizes that despite the first statement, the second one remains true.

Russian word order is flexible, but it is not random. Here:

• иногда = sometimes
• всё же = still / nevertheless
• спорят = argue

Putting the adverbial words before the verb is very natural in neutral Russian:

• иногда всё же спорят

This order highlights the frequency and the concessive nuance before you get to the action itself.

Other word orders are possible, but they would sound slightly different in emphasis. For example:

• но спорят иногда всё же — possible, but much less neutral
• но из‑за кубиков и маленькой машинки спорят иногда — also possible, but less natural here

Yes, very common. It is a useful pattern for expressing a nuanced contrast.

Basic idea:

• Не то чтобы X, но Y
• It’s not exactly that X, but Y
• I wouldn’t say X, but Y

Examples:

• Не то чтобы он ленивый, но работает мало.
  It’s not that he’s lazy, but he doesn’t work much.

• Не то чтобы мне не нравится фильм, но он слишком длинный.
  It’s not that I don’t like the film, but it’s too long.

In your sentence, it softens the first claim and makes the second one sound more balanced.

Yes, in many contexts ссорятся would work too:

• Не то чтобы дети часто ссорятся...

But the nuance changes a little.

• ссориться = to have a quarrel, to fall out, to be in conflict
• ругаться = to quarrel, argue noisily, use harsh words, sometimes to scold

In a sentence about children and toys, both are possible, but ругаются can sound a bit more like active verbal bickering, while ссорятся can sound more like being at odds with each other.

Yes. In the second clause, the subject is omitted because it is already clear from the first clause.

The full structure would be:

• Не то чтобы дети часто ругаются, но дети из‑за кубиков и маленькой машинки иногда всё же спорят.

But repeating дети would sound unnecessary. Russian often omits repeated subjects when the meaning is obvious.

So in the second clause, спорят still means the children argue.