Вона купила два банани, бо після тренування їй хочеться солодкого.

Because Ukrainian past tense agrees with the subject in gender and number.

Here the subject is Вона = she, so the verb must be feminine singular:

• він купив = he bought
• вона купила = she bought
• воно купило = it bought
• вони купили = they bought

So купила tells you the subject is a female person or a feminine noun.

After the numbers 2, 3, 4, Ukrainian usually uses the noun in the nominative plural.

So:

• один банан = one banana
• два банани = two bananas
• три банани = three bananas
• чотири банани = four bananas

But with 5 and higher, you normally get the genitive plural:

• п’ять бананів = five bananas

Also, два is the form used with masculine and neuter nouns. Since банан is masculine, два банани is correct.

The preposition після always takes the genitive case.

So тренування here is in the genitive singular. The tricky part is that for this word, the genitive singular looks exactly the same as the nominative singular:

• nominative: тренування
• genitive: тренування

So the form does not change visibly, but the case still does.

A clearer example with a different noun:

• урок = lesson
• після уроку = after the lesson

Because хочеться is part of an impersonal construction.

In Ukrainian, хотіти means to want, but хотітися / хочеться means something like:

• to feel like
• to have a craving for
• to want, in a spontaneous or emotional sense

With хочеться, the person who feels the desire goes in the dative case:

• мені хочеться = I feel like / I want
• тобі хочеться = you feel like
• їй хочеться = she feels like

So:

• вона хоче банан = she wants a banana
• їй хочеться банана / солодкого = she feels like having a banana / something sweet

Not quite.

• хоче = wants
• хочеться = feels like, has the urge for, craves

So їй хочеться солодкого sounds a bit softer and more natural for cravings, mood, or physical desire, especially with food.

Compare:

• Вона хоче піти додому. = She wants to go home.
• Їй хочеться спати. = She feels sleepy / She feels like sleeping.
• Їй хочеться солодкого. = She feels like having something sweet.

So in this sentence, хочеться is a very natural choice.

Here солодкого means something sweet or sweet food, and it is in the genitive case.

This is very common in Ukrainian when talking about a desire for food or drink, especially when the thing is indefinite or not a specific item.

So:

• їй хочеться солодкого = she feels like something sweet
• мені хочеться гарячого = I feel like something hot
• нам хочеться смачного = we feel like something tasty

You can think of an implied idea like something sweet behind it.

Compare:

• Вона любить солодке. = She likes sweets / sweet things in general.
• Їй хочеться солодкого. = She wants something sweet right now.

So солодкого is not just an adjective here; it is being used like a noun: sweet stuff / something sweet.

Yes. Both бо and тому що can mean because.

In this sentence:

• бо is shorter and very natural in everyday speech
• тому що is also correct, and can sound a bit more neutral or slightly more formal

So these are both fine:

• Вона купила два банани, бо після тренування їй хочеться солодкого.
• Вона купила два банани, тому що після тренування їй хочеться солодкого.

The meaning is basically the same.

Because бо introduces a subordinate clause, and in Ukrainian that clause is normally separated by a comma.

So the sentence has two parts:

1. Вона купила два банани
2. бо після тренування їй хочеться солодкого

That is why the comma appears before бо.

This is the same kind of punctuation you see with other conjunctions such as тому що, коли, якщо, and so on.

Yes. Ukrainian word order is fairly flexible, and changing it often changes focus rather than basic meaning.

For example, you could also say:

• Після тренування їй хочеться солодкого, тому вона купила два банани.
• Вона купила два банани, бо їй хочеться солодкого після тренування.
• Після тренування вона купила два банани, бо їй хочеться солодкого.

The original sentence is natural because it gives:

1. the main action first — she bought two bananas
2. then the reason — because after training she wants something sweet

So the original order sounds smooth and idiomatic.