Моя сестра купила новий шампунь, бо старий запах їй уже не подобається.

Because сестра is a feminine noun, and the possessive my has to agree with it in gender, number, and case.

• мій = masculine singular
• моя = feminine singular
• моє = neuter singular
• мої = plural

So:

• мій брат = my brother
• моя сестра = my sister

In the past tense, Ukrainian verbs agree with the subject in gender and number.

The subject is сестра (sister), which is feminine, so the verb is feminine too:

• він купив = he bought
• вона купила = she bought

So Моя сестра купила... means My sister bought...

The adjective новий (new) has to agree with шампунь in gender, number, and case.

шампунь is a masculine singular noun, so the adjective is also masculine singular:

• новий шампунь = new shampoo
• нова книга = new book
• нове місто = new city

Also, because шампунь is an inanimate masculine noun, its accusative singular looks the same as the nominative singular. Since купила takes a direct object, we need the accusative here, but it happens to look identical:

• nominative: новий шампунь
• accusative: новий шампунь

In Ukrainian, some masculine nouns end in a soft sign (ь). That does not make them feminine.

So шампунь is masculine, even though its ending may look unusual to an English speaker.

Other masculine nouns with -ь include:

• день = day
• вчитель = teacher
• король = king

You just have to learn the noun’s gender as part of the word.

бо means because. It introduces the reason:

• Моя сестра купила новий шампунь = My sister bought a new shampoo
• бо старий запах їй уже не подобається = because she no longer likes the old smell

бо is very common in everyday speech. Other ways to say because include:

• тому що = because
• оскільки = since / because

Of these, бо is especially short and conversational.

Yes, literally it means old smell or old scent.

In context, it means the smell/fragrance of the shampoo she used before. Ukrainian often leaves some things implied when the meaning is clear from context.

So this sentence naturally means something like:

• she bought a new shampoo because she doesn’t like the old one’s smell anymore

Even though шампуню is not repeated, the connection is understood.

їй is the dative singular form of вона (she).

It is used because the verb подобатися works differently from English to like.

In Ukrainian, the thing that is pleasing is the grammatical subject, and the person who experiences the liking is put in the dative:

• Мені подобається музика = I like music
  Literally: Music is pleasing to me
• Їй подобається запах = She likes the smell
  Literally: The smell is pleasing to her

So їй means to her.

Because Ukrainian commonly expresses to like with the verb подобатися, which means to be pleasing to.

That changes the structure:

• English: She likes the smell
• Ukrainian: The smell pleases her / The smell is pleasing to her

So in the sentence:

• старий запах їй уже не подобається

the subject is старий запах (the old smell), and їй means to her.

This is a very important pattern in Ukrainian.

Because its grammatical subject is запах (smell), which is singular.

Ukrainian verbs agree with their subject:

• запах подобається = the smell is pleasing / the smell is liked
• запахи подобаються = the smells are pleasing / the smells are liked

Even though English would say she doesn’t like it, Ukrainian is built around the smell as the subject, so the verb is singular.

уже means already or, in this context, often anymore / no longer together with negation.

So:

• їй уже не подобається = she doesn’t like it anymore / she no longer likes it

Without уже, the sentence would simply say she does not like it. With уже, it adds the idea of a change over time: she used to like it, but now she doesn’t.

Yes, word order in Ukrainian is fairly flexible, but different placements can affect emphasis.

In your sentence:

• старий запах їй уже не подобається

this sounds natural and neutral.

You may also hear:

• їй уже не подобається старий запах
• уже їй не подобається старий запах

These are grammatically possible, but the emphasis shifts slightly. Ukrainian often uses word order to highlight what is new, contrastive, or important in context.

For learners, the original order is a good model.

Ukrainian often uses не подобатися for not to like rather than a completely different everyday verb meaning to dislike.

So:

• подобається = is liked / is pleasing
• не подобається = is not liked / is not pleasing

There are stronger ways to express dislike, but не подобається is the normal, natural choice in many situations.

Yes. купила is the past tense of the perfective verb купити.

Perfective verbs usually present an action as completed:

• купити = to buy
• купила = bought

This fits the sentence because she completed the action of buying a new shampoo.

The imperfective partner is купувати:

• вона купувала шампунь = she was buying / used to buy shampoo

So купила is the natural choice when talking about one completed purchase.

Because бо introduces a subordinate clause giving the reason.

The sentence has two parts:

1. Моя сестра купила новий шампунь
2. бо старий запах їй уже не подобається

In Ukrainian, clauses like this are normally separated by a comma.

That would change the meaning.

• їй уже не подобається = she doesn’t like it anymore / she no longer likes it
  This is present tense
• їй не подобався = she didn’t like it
  This is past tense

Your sentence explains a present reason for a past action: she bought a new shampoo because now she doesn’t like the old smell anymore.

So the combination of купила + не подобається makes good sense.

It can mean either smell or scent, depending on context.

• запах is the standard general word
• in a shampoo context, English might naturally say smell, scent, or fragrance

So the Ukrainian word is normal and idiomatic here. If the context is cosmetics or perfume, English often prefers scent or fragrance, but запах itself is completely natural.