Gladak, ali glatka: the fleeting a and the muffling of consonants
This unit is made of adjectives almost entirely, and almost all of them end in -ak or -an. Put one into the feminine and it changes more than expected: gladak becomes glatka — smooth, redak — retka, nizak — niska — low. Two rules work together here, and English has neither: English adjectives bend without losing a letter (cheap, cheaper, cheapest). For example: “Сто је низак, а полица је ниска” — The table is low…
How it works
This unit is made of adjectives almost entirely, and almost all of them end in -ak or -an. Put one into the feminine and it changes more than expected: gladak becomes glatka — smooth, redak — retka, nizak — niska — low. Two rules work together here, and English has neither: English adjectives bend without losing a letter (cheap, cheaper, cheapest).
Rule one: the fleeting a. In the masculine singular an a sits between the last two consonants; in every other form it drops out. Kratak — but kratka, kratko, kratki. Težak — teška. Vlažan — vlažna. Tesan — tesna. This is not an exception but the norm: the masculine form is the only one where the a exists at all.
Rule two: muffling on paper. Serbian orthography writes what it hears: a voiced consonant before a voiceless one goes voiceless — and the letter changes with it. Gladak → glatka: the d became t before k. Redak → retka. Nizak → niska. English keeps the root spelling untouched across related forms ("photograph", "photography"); Serbian rewrites the sound.
Third, along the way: the short and the long form. The short form nov kaput — a new coat — against the long novi kaput — the new coat: the a/the split in miniature, which you met in the second wave. In -ak adjectives the long form also loses the fleeting a: gladak → glatki.
And where people slip. The comparative is built from the form WITHOUT the a, and the last consonant softens: gladak → glađi, redak → ređi, težak → teži, kratak → kraći. You cannot compute the softening from the spelling — just remember that the comparative of such words almost always carries a soft consonant.
Table
| masculine | feminine | neuter | comparative | in English |
|---|---|---|---|---|
| gladak | glatka | glatko | glađi | smooth |
| redak | retka | retko | ređi | sparse, thin |
| kratak | kratka | kratko | kraći | short |
| težak | teška | teško | teži | heavy |
| nizak | niska | nisko | niži | low |
| krhak | krhka | krhko | krhkiji | fragile |
| vlažan | vlažna | vlažno | vlažniji | damp |
| tesan | tesna | tesno | tesnji | tight |
By example
- Сто је низак, а полица је нискаSto je nizak, a polica je niskaThe table is low, and the shelf is low
- Пут је кратак, али је стаза још краћаPut je kratak, ali je staza još kraćaThe path is short, but the trail is even shorter
- Даска је глатка, а зид је храпавDaska je glatka, a zid je hrapavThe board is smooth, and the wall is rough
How the rule settles in your head
A rule is not memorized from an explanation. It is memorized from an attempt to use it and a mistake — that is why the app delivers it mixed in with words, not as a separate lesson: it resurfaces exactly where you forgot it.
Frequently asked
Gladak, ali glatka: how does it work in Serbian?
This unit is made of adjectives almost entirely, and almost all of them end in -ak or -an. Put one into the feminine and it changes more than expected: gladak becomes glatka — smooth, redak — retka, nizak — niska — low. Two rules work together here, and English has neither: English adjectives bend…
What does it look like in an example sentence Serbian?
“Сто је низак, а полица је ниска” (Sto je nizak, a polica je niska) — The table is low, and the shelf is low. A rule is easier to test on sentences like this than to memorize as a wording: what surfaces in conversation is the sentence.