The future with hteti plus the infinitive, affirmative and negative

Serbian has no separate future endings. To say what you will do, you keep the verb in its dictionary form — the infinitive, the form that ends in -ti or -ći (raditi, doći) — and add a tiny helper word in front of it that shows the person.

The helper: six little words

The helper is the short present of hteti (to want). It is unstressed, so it leans on the word next to it, exactly like je, sam, me and mi that you already know.

Put something in front of it and the two words stay apart: Ja ću raditi. — I will work. Sutra ćemo putovati. — Tomorrow we will travel. Like all unstressed little words, the helper can never be the first word of a sentence.

When the infinitive comes first, the two words merge

Whenever the infinitive stands in front of the helper — which usually means starting the clause with the verb — the helper hooks onto its back and the pair is written as one word. An infinitive in -ti loses that final -i first: raditi + ću becomes radiću. The two orders are both correct wherever the pair sits: U subotu ćemo krenuti and U subotu krenućemo say the same thing.

Verbs whose infinitive ends in -ći (doći, stići) do not merge in writing. Keep two words: Doći ću sutra. — I will come tomorrow.

Saying what you will not do

You already know two verbs that refuse ne in front of them and fuse it in instead: sam → nisam, imam → nemam. The future helper is the third one. Never ne ću — always the single word neću.

The negative helper is a full, stressed word, so it behaves differently from the little ću: it is happy to open the sentence, and it never merges with the verb. Neću putovati u petak. — I will not travel on Friday.

So the two series are not mirror images. Affirmative: something must come before ću, and radiću is written as one word. Negative: neću raditi — two words, and neću may start the sentence.

Asking about plans

In a question, either use da li with the little helper, or use the long stressed form hoću, hoćeš, hoće, hoćemo, hoćete, hoće with li: Da li ćeš doći u subotu? = Hoćeš li doći u subotu? — Will you come on Saturday? Both are everyday Serbian.

In speech you will often hear da plus the present instead of the infinitive: Sutra ću da radim means exactly the same as Sutra ću raditi. Recognise it; the infinitive pattern is the one to practise.