Croatian orthography follows Ljudevit Gaj's principle „piši kao što govoriš" — write as you speak. Where most European languages keep a word's root letters constant and let you say something different, Croatian usually writes the sound change into the spelling. So this is the page that ties the spelling system together: a survey of the regular alternations — jednačenje ("equalisation") and its relatives — that you must apply with your pen, plus the specific boundaries where the rule is deliberately suspended. The phonetics of voicing live on the voicing-assimilation page; here the question is purely orthographic: does the change get written, or not?
The changes Croatian writes
| Change | Croatian name | Written? | Example |
|---|---|---|---|
| Voicing assimilation | jednačenje po zvučnosti | yes | težak → teška |
| Place assimilation (s/z before š/ž etc.) | jednačenje po mjestu tvorbe | yes | list + je → lišće |
| n → m before b/p | (place assimilation) | yes | stan → stambeni |
| Jotation (t/d/s/z + j) | jotacija | yes | platiti → plaćen |
| l → o (in masc. l-participle) | vokalizacija | yes | radil → radio |
| Loss of doubled consonant | gubljenje suglasnika | yes | bez + zakonski → bezakonski |
The unifying takeaway: in standard Croatian, the writing, not the reading, is where the work happens. When you read, the spelling already shows you the right sound. When you build or inflect a word, you must perform the change yourself or you misspell it.
Voicing assimilation (jednačenje po zvučnosti)
When two obstruents collide, the second one decides the voicing and the first falls in line — and the result is written. A voiced consonant before a voiceless one devoices in spelling; a voiceless one before a voiced one voices.
| Build | Written result | Gloss |
|---|---|---|
| težak + -ka | teška | heavy (f.) — ž → š before k |
| sladak + -ka | slatka | sweet (f.) — d → t before k |
| rob + -stvo | ropstvo | slavery — b → p before s |
| svat + -ba | svadba | wedding — t → d before b (voicing) |
| vrabac → vrabaca? | vrapca | sparrow (gen.) — b → p before c |
Torba mi je preteška, ponesi je ti.
My bag is too heavy, you carry it. — 'teška': ž devoices to š before k, and it's written.
Cijeli je život proveo u ropstvu.
He spent his whole life in slavery. — 'ropstvo': rob + -stvo, b → p written.
Njihova svadba bila je u rujnu.
Their wedding was in September. — 'svadba': svat- voices to svad- before b, written with d.
Place assimilation (jednačenje po mjestu tvorbe)
Consonants also assimilate in place of articulation, and Croatian writes that too. Two patterns matter.
1. s/z become š/ž before a following soft consonant (č, ć, š, ž, lj, nj). The classic example is the collective list "leaf" + -je → lišće "foliage": the t drops, the s fronts to š, and the j fuses the t into ć. Similarly grozd "bunch" + -je → grožđe "grapes" (collective). The whole cluster softens together, and the spelling records it.
U jesen lišće požuti i pada.
In autumn the leaves turn yellow and fall. — 'lišće' from 'list' + '-je': s → š, t → ć, all written.
Kupila sam kilogram grožđa na tržnici.
I bought a kilo of grapes at the market. — 'grožđe' from 'grozd' + '-je': z → ž, d → đ.
2. n becomes m before b or p. A stem-final n shifts to the labial m before the labial stops b/p, and this is written. So stan "flat" → stambeni "residential, housing-"; zelen → in compounds; prehrana → prehrambeni "food-, nutritional". The n has assimilated its place to the following labial.
Cijene stambenih kredita rastu.
Housing-loan rates are rising. — 'stambeni' from 'stan': n → m before b, written. (formal)
Radi u prehrambenoj industriji.
She works in the food industry. — 'prehrambeni': n → m before b.
Jotation (jotacija) is also written
When t, d, s, z, l, n (and others) meet a softening j, they fuse into a single soft consonant — t → ć, d → đ, s → š, z → ž, l → lj, n → nj — and the result is spelled with the soft letter. This drives the comparative, the passive participle, and many verbal nouns, and it is fully written. The spelling detail for the affricates specifically (plaćen, mlađi) is on the č/ć and dž/đ spelling page, and the mechanism on the jotation page.
Posao je napokon završen i plaćen.
The job is finally finished and paid for. — 'plaćen': t + j → ć, written with ć.
The l → o change (vokalizacija)
This one surprises English speakers because it is not an assimilation at all but a vocalisation: a syllable-final or word-final l turns into o, and the spelling shows the o. Its most visible home is the masculine singular l-participle (the past-tense form): the historical -l ending becomes -o. So the verb raditi "to work" gives the participle radio (not radil) "(he) worked"; čitati → čitao "(he) read"; pisati → pisao "(he) wrote". The feminine and plural keep the l because it is no longer word-final: radila, radili.
| Verb | Masc. sg. (l → o) | Fem. sg. (l kept) |
|---|---|---|
| raditi (work) | radio | radila |
| čitati (read) | čitao | čitala |
| pisati (write) | pisao | pisala |
| vidjeti (see) | vidio | vidjela |
It also surfaces in nouns and adjectives whose stem-final l became word-final: posao "work" (gen. posla, where l returns medially), anđeo "angel" (gen. anđela), bijel keeps l but dio (from děl-) shows it. The rule: word-final or syllable-final l → written o; when an ending restores the l to medial position, the l comes back.
Jučer sam cijeli dan radio u vrtu.
Yesterday I worked in the garden all day. — masc. 'radio', l → o; cf. fem. 'radila'.
Pročitao sam knjigu i posudio je prijatelju.
I read the book and lent it to a friend. — 'pročitao', 'posudio': l → o in the masculine participle.
Nema posla, svi su otišli kući.
There's no work, everyone's gone home. — 'posao' (nom.) but 'posla' (gen.): the l returns when it's no longer final.
Where the change is NOT written
Croatian's „write as you speak" rule has principled exceptions, kept to protect recognisable morphemes. These are exactly where learners overcorrect.
1. d stays before s / š — protecting the prefixes pred-, od-, nad-, pod- and certain stems. You write predstava "performance", predsjednik "president", odšteta "compensation", not pretstava / pretsjednik. The d is kept even though casual speech may blur it.
Večeras idemo na kazališnu predstavu.
Tonight we're going to a theatre performance. — 'predstava' keeps its d before s; not 'pretstava'.
2. The change is not written before v or other sonorants — sonorants don't take part in voicing, so -stvo survives intact in društvo "society", bogatstvo "wealth", and t/s stay put in tvoj, svoj, cvijet.
Cijelo društvo se okupilo za stolom.
The whole company gathered at the table. — '-stvo' unchanged before v in 'društvo'.
3. Some prefix+stem boundaries keep the root consonant for transparency: gradski "urban" keeps the d of grad before s (you write gradski, not gratski), like predsjednik.
Gradski prijevoz danas ne radi.
City transport isn't running today. — 'gradski' keeps d before s, no devoicing written.
Common Mistakes
❌ Torba mi je previše težka.
Incorrect — ž devoices to š before k, and it's written: 'teška'.
✅ Torba mi je previše teška.
My bag is too heavy. — 'teška', the change is written.
❌ Naš novi pretsjednik dolazi sutra.
Incorrect overcorrection — d is kept before s: 'predsjednik'.
✅ Naš novi predsjednik dolazi sutra.
Our new president arrives tomorrow. — protected prefix seam, d stays.
❌ Jučer sam radil cijeli dan.
Incorrect — the masculine l-participle vocalises: 'radio', not 'radil'.
✅ Jučer sam radio cijeli dan.
Yesterday I worked all day. — l → o in the masculine: 'radio'.
❌ U jesen listje pada.
Incorrect — list + je gives 'lišće' (place assimilation + jotation), written.
✅ U jesen lišće pada.
In autumn the leaves fall. — 'lišće', the whole cluster softens in spelling.
❌ Cijene stanbenih kredita rastu.
Incorrect — n assimilates to m before b: 'stambeni', not 'stanbeni'.
✅ Cijene stambenih kredita rastu.
Housing-loan rates are rising. — n → m before b, written.
Key Takeaways
- Croatian follows „piši kao što govoriš": it writes most sound changes, so the spelling is a record of the alternation, not just the pronunciation.
- Written: voicing assimilation (teška, slatka, ropstvo, svadba); place assimilation (lišće, grožđe; stan → stambeni); jotation (plaćen, mlađi); the l → o change in masculine l-participles (radio, čitao).
- Not written (protected boundaries): d before s/š (predstava, predsjednik, odšteta), nothing before v / sonorants (društvo, bogatstvo), and clarity-keeping prefix seams (gradski).
- The real effort is on the writing side: when you inflect or derive, apply the change. The typical error is leaving the base unchanged (težka, listje, stanbeni, radil) or overcorrecting a protected d (pretsjednik).
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Start learning Croatian→Related Topics
- Voicing Assimilation in ClustersB1 — How adjacent consonants agree in voicing, and when it is written.
- Final Consonants and Difficult ClustersB1 — Whether finals devoice, and tackling consonant clusters.
- Spelling č/ć and dž/đB1 — How to choose the right affricate letter in derivation despite the spoken merger — č from k-palatalisation and many roots, ć from t-jotation and the -ić/-ica suffixes, đ from d-jotation, and rare borrowed dž.
- Jotation (jotacija)B2 — The consonant + j fusion behind comparatives, passive participles, and verbal nouns.
- The Yat Reflex: Spelling ije, je, e, iB1 — How standard (ijekavian) Croatian spells the old yat vowel — long ije vs short je, the je → lje/nje fusion, and the e and i reductions — driven mostly by syllable length.