У моєї тітки є онук і онука.

A very common way to express possession in Ukrainian is:

у/в + Genitive + є + thing possessed

So У моєї тітки є онук і онука literally means something like:

At my aunt, there is a grandson and a granddaughter

But in natural English, that becomes:

My aunt has a grandson and a granddaughter.

Ukrainian does have a verb related to having—мати—but in ordinary speech, possession is often expressed with у/в ... є.

For example:

• У мене є брат. = I have a brother.
• У нас є машина. = We have a car.

This is one of the most important sentence patterns to learn early.

Because after у/в in this possession pattern, Ukrainian uses the genitive case.

The basic forms are:

• моя = my
• тітка = aunt

But in this sentence they become:

• моєї = genitive feminine singular of моя
• тітки = genitive singular of тітка

So:

• моя тітка = my aunt
• у моєї тітки = of/at my aunt in the possession structure

This is why you cannot say У моя тітка є... That would be grammatically wrong.

Є means is/are in the sense of there is / there are.

In this sentence, it marks existence:

• У моєї тітки є онук і онука. = My aunt has a grandson and a granddaughter.

More literally:

• At my aunt there is a grandson and a granddaughter.

So є is not really the same as English has, even though that is how we translate the whole sentence.

Yes, very often in everyday Ukrainian, especially in casual speech, є can be omitted:

• У моєї тітки онук і онука.

This still means:

My aunt has a grandson and a granddaughter.

Using є can sound a bit more explicit or neutral, and it is very common and correct. Omitting it is also common in conversation.

So both are possible.

Yes. У and В are often variants of the same preposition, and the choice is usually made for ease of pronunciation and smooth sound.

So you may see:

• У моєї тітки є...
• В моєї тітки є...

Both are possible, though У моєї тітки sounds smoother here to many speakers.

This alternation is very common in Ukrainian and is not usually a change in meaning.

They are two different nouns:

• онук = grandson
• онука = granddaughter

Ukrainian usually marks gender directly in the noun, so unlike English, these are not just one word with extra explanation.

Here the sentence says your aunt has:

• one grandson
• and one granddaughter

So:

• онук = masculine
• онука = feminine

Because Ukrainian has no articles.

English says:

• a grandson
• a granddaughter
• the aunt

Ukrainian does not have separate words for a/an/the. The meaning is understood from context.

So:

• онук can mean a grandson or sometimes the grandson, depending on context
• онука can mean a granddaughter or the granddaughter

In this sentence, the natural English translation uses a:

My aunt has a grandson and a granddaughter.

The word order is fairly natural as written, but Ukrainian word order is more flexible than English.

The neutral version is:

• У моєї тітки є онук і онука.

You may also hear:

• Онук і онука є у моєї тітки.
• У моєї тітки онук і онука.

These can sound more marked, emphatic, or context-dependent.

For a learner, the safest pattern is:

У + possessor in genitive + є + possessed thing

That pattern will work very well in many situations.

Yes. І means and.

So:

• онук і онука = a grandson and a granddaughter

Ukrainian also has й as a variant of і, often chosen for smoother pronunciation, just like у/в alternate.

For example, depending on surrounding sounds, you might see either і or й, but the meaning is still and.

The basic form is:

• моя тітка = my aunt

That is the nominative form, the form you would usually find in vocabulary lists.

In the sentence, it changes to:

• моєї тітки

because of the possession pattern with у + genitive.

So it is useful to compare:

• моя тітка = my aunt
• у моєї тітки = my aunt has / at my aunt's

You can reuse the same pattern very easily:

• У мене є брат. = I have a brother.
• У мого дядька є донька. = My uncle has a daughter.
• У нашої бабусі є кіт. = Our grandmother has a cat.

So the pattern is:

У + genitive form of the possessor + є + noun

This sentence is a great model for building many other possession sentences in Ukrainian.