The suffix -id- forms a noun for an offspring or descendant of what comes before it. With animals it normally names an immature member of the species: hundo → hundido “puppy,” kato → katido “kitten.” With people it can mark descent rather than youth, and established figurative uses extend the idea to plants, dynasties, and language families.
English makes learners memorize puppy, kitten, calf, chick, and tadpole. Esperanto offers the general relationship parent or source + -id-, while still allowing frequent derived words to develop conventional meanings.
Source on the left, offspring as the head
Place -id- after the source species or ancestor and before the grammatical ending:
| Source | Derived word | Meaning |
|---|---|---|
| hundo | hundido | young dog; puppy |
| kato | katido | young cat; kitten |
| bovo | bovido | young bovine; calf |
| arbo | arbido | young tree; sapling |
The suffix is the semantic head “offspring/descendant.” The material before it answers “offspring of what?” A hundido is not merely something doglike; it is a young member descended from dogs.
La hundido ekdormis sub la kuireja tablo.
The puppy fell asleep under the kitchen table.
Ĉu la katidoj jam povas manĝi sen la patrino?
Can the kittens eat without their mother yet?
The suffix does not itself specify sex. A katido may be male or female unless context says otherwise.
Offspring is not the same as smallness
The contrast with -et- is fundamental:
La hundido estas juna; la hundeto de la najbaro estas maljuna sed tre malgranda.
The puppy is young; the neighbor's little dog is old but very small.
Hundido classifies by age and descent. Hundeto scales down the size or adds an affectionate nuance and can refer to an adult. A large puppy remains a hundido; a small elderly dog can be a hundeto.
Tiu ĉevalido jam estas preskaŭ tiel alta kiel sia patrino.
That foal is already almost as tall as its mother.
Physical size therefore does not cancel the offspring term. The biological stage is what matters.
The suffix does not specify an exact age boundary. What counts as immature depends on the species and context: a nearly full-sized horse can still be a ĉevalido, while speakers may stop calling a household animal hundido at different stages. This is ordinary lexical flexibility, not a defect in the morphology.
La bestkuracisto klarigis, ke la granda hundo ankoraŭ estas ido kaj bezonas specialan nutraĵon.
The veterinarian explained that the large dog is still a juvenile and needs special food.
Animals and lexicalized everyday words
Animal names are the most productive domain. Birdido is a young bird, ranido a young frog, and kokido a young chicken. Context may narrow a common word further: kokido also occurs for chicken as food, just as English uses an animal term for meat.
La birdo portas vermon al siaj idoj en la nesto.
The bird is carrying a worm to its chicks in the nest.
Ni mendis rostitan kokidon kun terpomoj.
We ordered roast chicken with potatoes.
Here idoj stands independently for offspring because the parent species is already known. The simple noun ido most readily evokes a young animal; idaro is a collective for offspring or descendants.
La biologoj observis la idaron sen tuŝi la neston.
The biologists observed the brood without touching the nest.
Productivity does not guarantee that every conceivable animal term is equally usual. A species may have a conventional simple name for a developmental stage, especially in scientific terminology. Use -id- when the general offspring relation is intended; learn specialized terms where precision matters.
Human descent and historical titles
With a human base, -id- means a child or descendant and need not imply that the person is young. It is most established with royal or noble titles and in historical names.
La reĝido revenis al la kortego post longa ekzilo.
The king's child returned to the royal court after a long exile.
The word reĝido identifies descent from a monarch. It does not necessarily mean “young prince,” and it does not itself specify male sex. In actual historical translation, an established title such as princo or princino may be more idiomatic than a mechanically derived word.
Dynasty names can treat a named ancestor as the source. Karolidoj refers to the Carolingian dynasty descended from Charlemagne, and Timuridoj to descendants of Timur. Such names are (historical, academic) and lexicalized; do not invent an -idoj dynasty label for any family without communicative context.
La prelego komparis la arton de la Karolidoj kun tiu de postaj dinastioj.
The lecture compared Carolingian art with that of later dynasties.
Ĉu ŝi estas lia filino? — Ne, ŝi estas pli malproksima ido de la sama familio.
Is she his daughter? — No, she is a more distant descendant of the same family.
In ordinary family conversation, use precise kinship words such as filo, filino, nepo, or nepino when known. Ido is broader and can sound genealogical or biological.
Human descent also differs from nationality or residence. A historical izraelido is presented as a descendant of the person Israel, whereas an israelano is an inhabitant or citizen of the country Israelo. The words can refer to overlapping people, but their semantic relations are not interchangeable.
En la historia teksto, izraelido montras devenon, ne simple modernan civitanecon.
In the historical text, izraelido indicates descent, not simply modern citizenship.
Plants and figurative descent
With a plant base, -id- can name a young plant: arbido is a sapling. This use is transparent but less universally productive than animal offspring.
Ni plantis du arbidojn por anstataŭigi la falintan arbon.
We planted two saplings to replace the fallen tree.
Figuratively, descent can mean historical development. Latinidaj lingvoj are languages descended from Latin—the Romance languages. The adjective -ida expresses the same descent relation without naming an individual offspring.
La franca kaj la portugala estas latinidaj lingvoj.
French and Portuguese are Romance languages.
This established (academic) use concerns genealogy between languages, not physical birth. A novel figurative -id- word may be understandable, but it needs a clear source-to-descendant relationship rather than mere similarity.
Affix order and sex marking
When affixes stack, each step contributes scope:
- kat-id-in-o → katidino, a female kitten
- kat-in-id-o → katinido, an offspring specifically of a female cat
The first is the useful ordinary formation when the kitten's sex matters. The second is structurally interpretable but usually needlessly specifies the mother's sex; katido already entails feline parentage.
La bestkuracisto diris, ke la plej malgranda katidino estas tute sana.
The veterinarian said that the smallest female kitten is completely healthy.
The distinction demonstrates why stacking cannot be random. -in- after -id- classifies the offspring; -id- after an explicitly female parent base identifies the source. See affix stacking and scope.
Compound order is equally consistent. The source precedes the offspring head: lupido, not an English-influenced reversal such as idlupo.
Norm, convention, and coinage
-id- is a Fundamenta suffix, and the animal-offspring pattern is fully standard. Accepted extensions to human descendants, young plants, dynasties, and language families are also well attested, but their productivity differs. An immediately transparent zebrido “zebra foal” can work in context, yet a familiar community term may be preferable.
Pedagogical recommendation: use -id- freely for general animal offspring and recognized descent terms. For people, prefer ordinary kinship vocabulary unless broad or historical descent is genuinely the point. For technical species and historical groups, verify the established term rather than assuming a logical coinage is conventional.
Common Mistakes
1. Confusing offspring with small size.
❌ Ĉiu hundeto estas hundido.
Incorrect: a small dog is not necessarily a puppy.
✅ La hundeto estas dekdujara, do ĝi ne estas hundido.
The little dog is twelve years old, so it is not a puppy.
2. Reversing the source and the offspring head.
❌ La infanoj trovis idkaton en la ĝardeno.
Incorrectly ordered for ‘kitten.’
✅ La infanoj trovis katidon en la ĝardeno.
The children found a kitten in the garden.
3. Assuming -id- marks male sex.
❌ Katido ĉiam estas vira kato.
Incorrect: -id- marks offspring, not sex.
✅ La katido estas ina; ĝi estas katidino.
The kitten is female; it is a female kitten.
4. Replacing an ordinary kinship term without reason.
❌ Jen mia ido, Ana.
Awkward in ordinary introduction if Ana is simply your daughter; ido sounds broad or biological.
✅ Jen mia filino, Ana.
This is my daughter, Ana.
Key Takeaways
- -id- names an offspring or descendant; the preceding base names the source.
- Animal -ido words normally indicate youth, whereas human descent may extend across generations.
- -id- differs from diminutive -et-: age/descent is not size.
- The suffix is sex-neutral; later -in- can specify a female offspring.
- Plant, dynastic, and linguistic uses are established extensions, not a license for opaque coinages.
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Start learning Esperanto →Related Topics
- -in-: Female SexA2 — Use -in- to specify female sex while preserving neutral person and animal roots when sex is irrelevant.
- -et-: DiminutionA2 — Use -et- to make meanings smaller, weaker, shorter, or more affectionate while keeping the base meaning recognizable.
- Affix Stacking and ScopeB2 — Interpret and build multi-affix Esperanto words by applying each layer in order and keeping the semantic head and participant roles clear.
- People and Animate ReferenceA2 — How Esperanto names people and animals without grammatical gender while marking number, case, and relevant natural sex.
- Natural Sex and Lexical GenderB1 — How sex can be part of a root’s meaning or added explicitly without creating grammatical gender agreement.