У моей дочери розовый рюкзак, а у сына — коричневый пенал.

Russian usually expresses possession with the pattern:

у + possessor (genitive) + possessed thing

So:

• У моей дочери розовый рюкзак = literally, By/at my daughter there is a pink backpack
• Natural English: My daughter has a pink backpack

This is the normal way to say someone has something in Russian.

Russian does have иметь (to have), but it is much less common in everyday speech for simple possession. Using у ... sounds more natural here.

Because after у in this possession pattern, the person who possesses something goes into the genitive case.

So:

• дочь → дочери
• сын → сына

That is why the sentence says:

• у моей дочери
• у сына

not у моя дочь or у сын.

The adjective/pronoun мой / моя / моё / мои must agree with the noun in gender, number, and case.

Since дочери is:

• feminine
• singular
• genitive

the form of моя changes to моей.

So:

• nominative: моя дочь = my daughter
• genitive after у: у моей дочери

This is just agreement: the pronoun changes because the noun changes.

In this kind of possession sentence, the possessor goes in the genitive after у, but the thing possessed normally stays in the nominative.

So:

• у моей дочери = possessor in genitive
• розовый рюкзак = thing possessed, nominative
• у сына = possessor in genitive
• коричневый пенал = thing possessed, nominative

A useful pattern to remember is:

У + genitive + nominative

Example:

• У брата машина = My brother has a car

Because they agree with the nouns they describe:

• рюкзак is masculine → розовый рюкзак
• пенал is masculine → коричневый пенал

In Russian, adjectives change to match the noun’s:

• gender
• number
• case

So if the noun were feminine, the adjective would change too:

• розовая сумка
• коричневая коробка

But here both nouns are masculine singular nominative, so the adjective endings are -ый.

The dash shows that something has been left out because it is understood.

The full version could be:

У моей дочери розовый рюкзак, а у сына коричневый пенал.

or even more explicitly:

У моей дочери есть розовый рюкзак, а у сына есть коричневый пенал.

The dash helps mark the pause and contrast in the second part. It often appears when Russian omits repeated words or structure that the reader can easily supply.

So the dash here is not translating a specific English word. It is more of a punctuation signal: the same kind of statement continues, but in contrast.

А often connects two ideas with a sense of contrast or comparison, even when both statements are true.

Here the sentence is comparing:

• the daughter’s item
• the son’s item

So а works well:

• У моей дочери розовый рюкзак, а у сына — коричневый пенал.

This feels like:

• My daughter has a pink backpack, while my son has a brown pencil case.

If you used и, it would sound more like simple addition:

• ... and my son has ...

That is possible in some contexts, but а is more natural when setting the two side by side.

It could. У моего сына is grammatically correct.

But Russian often omits repeated information when it is obvious from context.

The first half already says моей дочери (my daughter), so in the second half у сына naturally means my son in this context.

This makes the sentence lighter and less repetitive.

So these are both possible:

• У моей дочери розовый рюкзак, а у сына — коричневый пенал.
• У моей дочери розовый рюкзак, а у моего сына — коричневый пенал.

The version without моего sounds more economical and natural in a contrast like this.

In a way, yes.

Russian often leaves out есть in present-tense possession sentences.

So:

• У моей дочери розовый рюкзак
  can be understood as
• У моей дочери есть розовый рюкзак

Both are possible, but in ordinary speech the version without есть is very common and often more neutral.

Adding есть can sometimes sound more explicit or emphatic, as in:

• She does have a pink backpack

For a beginner, it is safest to learn that in the present tense, Russian often says possession without есть.

Despite how it looks, пенал usually means a pencil case or school supply case, not specifically a case only for pens.

So in this sentence:

• коричневый пенал = a brown pencil case

This is a very common school-related word in Russian.

Yes. Russian word order is more flexible than English, but the original order is very natural.

The sentence:

У моей дочери розовый рюкзак, а у сына — коричневый пенал.

puts the possessors first, which is a common way to frame possession and comparison.

You might also see variations for emphasis, but they can change the focus slightly. For example:

• Розовый рюкзак у моей дочери, а коричневый пенал — у сына.

This sounds more contrastive, focusing on the objects first.

For learners, the original version is the best basic model: У + possessor + item.

In negative possession, Russian often changes the possessed thing into the genitive too.

For example:

• У моей дочери нет розового рюкзака.
• У сына нет коричневого пенала.

Notice:

• рюкзак → рюкзака
• пенал → пенала

So in an affirmative sentence like the one you were given, the possessed thing is nominative. In a negative sentence with нет, it usually becomes genitive.

This is a very important pattern:

• affirmative: У дочери розовый рюкзак
• negative: У дочери нет розового рюкзака