Вишні, груші й сливи є в кошику.

Є here works like an existential verb: it expresses that something is present / exists somewhere. In English, that is often translated with there is / there are.

So in this sentence, є is not just a normal plural are that agrees with the subject the way English does. Ukrainian є stays the same form here whether the things are singular or plural.

That is why you get є with вишні, груші й сливи, even though those nouns are plural.

Yes, often you can.

Ukrainian very often omits a present-tense form of to be, especially in simple statements. So Вишні, груші й сливи в кошику is also possible.

The version with є sounds more explicitly like there are cherries, pears, and plums in the basket. It emphasizes existence or presence a bit more.

They are in the nominative plural.

In this sentence, they are the things that are present in the basket, so they appear as the main nouns of the sentence.

Their singular forms are:

• вишня
• груша
• слива

The plural forms here are:

• вишні
• груші
• сливи

Because в here means in as a location, not movement.

When в / у means being inside a place, Ukrainian normally uses the locative case. So:

• в кошику = in the basket

The base form is кошик, but after в for location it becomes кошику.

A useful contrast is:

• в кошику = in the basket
• в кошик = into the basket

So в кошику answers where?, while в кошик would answer where to?

Й and і both mean and here.

Ukrainian often chooses between them for euphony: making the sentence sound smoother. After a word ending in a vowel, й often sounds more natural.

So:

• груші й сливи sounds smooth

You could also say груші і сливи, and the meaning would be the same. The choice is mostly about sound and flow.

For the same general reason: euphony.

Both в and у can mean in. Ukrainian often alternates between them so the sentence is easier to pronounce.

So both of these are possible:

• є в кошику
• є у кошику

The meaning does not change. The speaker chooses the version that sounds better in context.

Yes, you could, and that version is often very natural.

Both are grammatical, but the emphasis is a little different:

• Вишні, груші й сливи є в кошику puts the fruit list first.
• У кошику є вишні, груші й сливи starts with the location and then tells you what is there.

The second version is often more typical when introducing the contents of something.

This is a normal list.

In Ukrainian, when you list several items, you usually put commas between the earlier items, but not before the final й / і / та.

So:

• Вишні, груші й сливи

This works like cherries, pears and plums in English. Ukrainian normally does not use an Oxford comma before the final conjunction in a simple list.

No. Ukrainian has no articles.

So the sentence does not contain anything directly equivalent to English the, a, or some. Whether the meaning is more like the cherries or some cherries depends on context.

That means a learner should not look for a separate word for the in this sentence, because Ukrainian simply does not use articles that way.

Some of them can mean both, depending on context.

In Ukrainian, words like груша and слива can refer to the fruit or the tree. Context tells you which one is meant.

In this sentence, because the things are in a basket, the meaning is clearly the fruits, not the trees. So there is no real ambiguity here.