Learn Hardcore Croatian: Ne želim šećer u čaju; pijem ga bez šećera. - I don’t want sugar in tea; I drink it without sugar.

Ga is the unstressed object pronoun for “him/it” (masculine or neuter singular). Here it refers to čaj (tea), because you drink tea, not sugar. So pijem ga = “I drink it (the tea).”

Why not use je instead of ga?

Je/ju is the feminine singular object pronoun. Since čaj is masculine, you use ga. You would use je/ju with a feminine noun like kava (coffee): Pijem je/ju bez šećera.

Why does šećer stay the same after ne želim?

Šećer is a masculine inanimate noun. In the accusative singular, masculine inanimate nouns have the same form as the nominative, so (ne) želim šećer is correct. There’s no extra ending needed.

What case is u čaju, and why is it used?

U čaju is locative singular. After u you use:

locative to express location (in/at): u čaju = “in the tea”
accusative to express motion into: u čaj = “into the tea”

So would u čaj ever be correct here?

Not for this meaning. Ne želim šećer u čaju describes a state (sugar present in the tea). U čaj would be used with a motion verb like staviti (to put): Ne želim da stavljaš šećer u čaj.

Why is it bez šećera and not bez šećer?

The preposition bez (“without”) always takes the genitive case. The genitive singular of šećer is šećera, hence bez šećera.

Could ga be referring to šećer instead of čaj?

Grammatically, both čaj and šećer are masculine, so in theory ga could match either. But the verb piti (to drink) makes the intended referent clear: you drink tea, not sugar. If you want to avoid any chance of ambiguity, say Pijem čaj bez šećera.

Is the semicolon in Ne želim šećer u čaju; pijem ga bez šećera. necessary?

It’s a good choice: it links two closely related independent clauses. You could also use:

a period: Ne želim šećer u čaju. Pijem ga bez šećera.
a dash: Ne želim šećer u čaju — pijem ga bez šećera.
or a conjunction: Ne želim šećer u čaju, jer pijem čaj bez šećera.
A plain comma without a conjunction is less standard.

Can I move ga somewhere else, like Ga pijem bez šećera?

No. Clitic pronouns like ga can’t start a clause. They typically occupy the “second position.” Acceptable options include:

Pijem ga bez šećera.
Ja ga pijem bez šećera.
Čaj ga pijem bez šećera (possible but marked/stylistic).
Avoid starting the clause with Ga.

Is Neću šećer u čaju also correct? What’s the nuance vs Ne želim?

It’s grammatical, but:

Ne želim = “I don’t want” (neutral/polite statement of preference).
Neću = “I won’t / I refuse” or “I don’t want (to)” (stronger, more categorical; also the negative of the future auxiliary).
For ordering or polite preference, (Ne) želim or Molim (čaj) bez šećera sounds better.

Do I need to say ja (Ja ne želim…)?

No. Croatian verb endings show the subject, so Ne želim… already means “I don’t want…”. You can add ja for emphasis or contrast: Ja ne želim šećer u čaju.

Why is šećer singular? Could I say a plural like šećeri?

Šećer is a mass noun, so singular is used for an unspecified amount. The plural šećeri usually means “types of sugar” (e.g., brown and white sugars), not the sweetener in your cup.

Is pijem the right aspect? What about popijem?

Yes. Pijem (imperfective) expresses a general habit or ongoing action.
Popijem (perfective) focuses on a single completed act (“I’ll drink it up”). For a one-off future you could say: Popit ću ga bez šećera. For general preference/habit, stick with pijem.

Is Ne želim u čaju šećer acceptable word order?

It’s understandable but sounds marked. The neutral order is object + prepositional phrase: Ne želim šećer u čaju. Changing the order can add focus or sound stylistically odd.

Could I drop ga and just say Pijem bez šećera?

Not by itself; it sounds incomplete (“I drink without sugar” … what?). Either keep ga or repeat the noun: Pijem čaj bez šećera.

How would this change with other drinks?

Feminine noun (kava): Ne želim šećer u kavi; pijem je/ju bez šećera.
Neuter noun (mlijeko): Ne želim šećer u mlijeku; pijem ga bez šećera.
In practice, ga is used for masculine and neuter singular; je/ju for feminine.

Why is it čaju and not čaja or čajem?

Different cases:

čaju = locative (after u for location: “in the tea”)
čaja = genitive (“of the tea”)
čajem = instrumental (“with the tea”)
Here, location is intended, so u čaju is required.

Should I say u mom čaju or u svom čaju?

Both are possible:

u mom čaju = “in my tea”
u svom čaju = “in my own tea” (reflexive possessive; used when the subject is also the possessor).
Since the subject is “I,” u svom čaju is often preferred in careful style.