Ti voliš kafu, ali ja volim čaj.

Because Serbian verbs change depending on the subject.

The verb here is voleti = to love / to like. In the present tense:

• ja volim = I like
• ti voliš = you like
• on/ona/ono voli = he/she/it likes
• mi volimo = we like
• vi volite = you (plural/formal) like
• oni/one/ona vole = they like

So:

• ti voliš = you like
• ja volim = I like

This is similar to how English says I am but you are, except Serbian does this with many verbs.

Because Serbian uses cases, and direct objects usually go into the accusative case.

In this sentence, coffee and tea are the things being liked, so they are direct objects.

• kafa → kafu
• čaj → čaj

This difference happens because different nouns change in different ways.

kafa

This is a feminine noun, and its accusative singular is:

• kafa = nominative
• kafu = accusative

čaj

This is a masculine noun, and for many masculine inanimate nouns, the accusative is the same as the nominative:

• čaj = nominative
• čaj = accusative

So the sentence uses:

• voliš kafu
• volim čaj

Ali means but.

It connects two contrasting ideas:

• Ti voliš kafu = You like coffee
• ali ja volim čaj = but I like tea

It is a very common conjunction in Serbian.

Very often, you can leave them out.

Serbian usually makes the subject clear from the verb ending:

• Voliš kafu already means You like coffee
• Volim čaj already means I like tea

So the full sentence could also be:

• Voliš kafu, ali volim čaj.

Including ti and ja adds emphasis or contrast. In this sentence, that makes sense, because the speaker is contrasting you and I:

• Ti like coffee, but I like tea.

So the pronouns are not wrong at all—they just make the contrast stronger.

It can mean both, depending on context.

In sentences about food, drinks, hobbies, and general preferences, voleti is often best translated as to like:

• Volim čaj = I like tea

With people, it can mean to love:

• Volim te = I love you

So in this sentence, it is understood as like, not strong romantic love.

Yes, Serbian word order is more flexible than English word order.

The given sentence is very natural and neutral, especially with contrast:

• Ti voliš kafu, ali ja volim čaj.

But Serbian can move words around for emphasis. For example:

• Kafu ti voliš, ali ja volim čaj.
• Ja volim čaj, ali ti voliš kafu.

These versions may sound more marked or emphasize different parts.

For learners, the safest pattern is:

subject + verb + object

So:

• Ti voliš kafu.
• Ja volim čaj.

Normally, ti is lowercase.

In Serbian, the pronoun Ti is sometimes capitalized in writing when addressing one person politely or respectfully, especially in:

• letters
• emails
• formal messages

But in ordinary sentences, it is usually written lowercase:

• ti

Since this sentence is just a normal example, lowercase is the standard choice.

These letters represent sounds that English speakers often need to practice.

š

Pronounced like sh in shoe

• voliš sounds roughly like VOH-leesh

č

Pronounced roughly like ch in church, but often a bit firmer/cleaner in Serbian

• čaj sounds roughly like chai

So:

• voliš → the last sound is sh
• čaj → starts with ch

Also:

• kafu = KAH-foo
• ali = AH-lee
• ja = yah

Ti is singular informal you.

Use ti when speaking to:

• one friend
• one family member
• one child
• one person you are on informal terms with

For you plural or formal singular, Serbian uses vi:

• Ti voliš kafu. = You like coffee. (one person, informal)
• Vi volite kafu. = You like coffee. (plural, or one person formally)

This is an important distinction in Serbian.

Because Serbian does not need an extra helping verb like English do for normal present-tense statements.

English says:

• I like tea
• I do like tea for emphasis

Serbian simply uses the main verb:

• Volim čaj.

If you want emphasis, Serbian usually changes intonation, word order, or adds another word—not a separate do-type helper in the same way English does.

Yes, voleti is very natural for talking about preferences in food and drink.

So these are normal:

• Volim kafu. = I like coffee.
• Volim čaj. = I like tea.

You may also hear sviđati se, but that works differently grammatically and is often closer to to appeal to / to be pleasing to.

For a beginner, voleti is the easiest and most useful verb for sentences like this one.

They are in the nominative case, because they are the subjects of the verbs.

• ti = you
• ja = I

They are the people doing the action of liking.

Meanwhile, kafu and čaj are the objects, so they are in the accusative.

So the structure is:

• Ti = subject, nominative
• voliš = verb
• kafu = direct object, accusative

and

• ja = subject, nominative
• volim = verb
• čaj = direct object, accusative

No, those forms would be incorrect here.

You need the correct object forms:

• kafu, not kava
• čaj, not čaja

Why?

Because after volim / voliš, the thing liked is a direct object, so Serbian uses the accusative case.

Correct sentence:

• Ti voliš kafu, ali ja volim čaj.

For beginners, it helps to memorize whole chunks:

• volim kafu
• volim čaj
• voliš kafu
• voliš čaj