Esperanto Compound Words: vaporŝipo, tagmezo and Reading Long Words From the Right

You have been building compound words since chapter two without being told. Eniri is en plus iri, to go in. Foriri is for plus iri, to go away. Alveni, kunveni, eliri, interparoli: preposition on the front, verb on the back, one word out the other end. Nothing in that list needed a dictionary's permission.

This article is that same machinery, unhidden, and applied to roots of any kind.

The rule: the last root wins

Take the classic example, which Zamenhof himself used:

vaporo (steam) + ŝipo (ship) = vaporŝipo, a steamship

A vaporŝipo is a ship. It is not a variety of steam. The final root is the head: it says what the thing fundamentally is, and every root to its left narrows it down.

Reverse them and you reverse the meaning:

Same two roots, two different animals. Or rather, one animal and one noise.

English does this too, and does it in the same direction: a houseboat floats, a boathouse does not. What English cannot decide is whether to write the thing solid, hyphenated or spaced, which is why ice cream, icebox and ice-cold all exist. Esperanto writes it solid and stops thinking about it.

One word, one ending, one stress

Only the final root carries the grammatical ending, and the compound then declines as a single ordinary word:

Mi vidis du grandajn vaporŝipojn. - I saw two big steamships.

-oj- for the plural, -n because it is the object (the accusative article covers why). No part of vapor- changes, ever.

The stress follows from this. Esperanto stress is always on the penultimate syllable of the word, and a compound is one word, so it takes one stress: va-por-ŜI-po. If you hear two stresses you are hearing two words.

The linking -o-, and when to drop it

Between the roots you may insert a linking vowel. In practice it is -o-, whatever the first root's own part of speech happens to be, and the only real decision is whether to keep it.

The working rule is pronunciation. Drop it where the join is comfortable, keep it where it is not:

Look at tagmezo and noktomezo together, because they are the same compound built on the same second root and they come out differently. Tagm- is easy. Noktm- is a pile of four consonants that nobody says twice, so the -o- stays. That is the whole rule, and it is a rule about your mouth rather than about grammar.

Two footnotes. First, both forms are usually acceptable and usually attested somewhere, so this is a question of sounding fluent rather than of being right: nobody will misparse dormĉambro. Second, other linking vowels turn up in a small handful of words built from a whole word rather than a bare root, of which multekosta (expensive, from multe plus kosta) is the one you will actually meet. Do not go looking for more.

Prefer an affix where one exists

Esperanto has around forty affixes, and the word-building article covers the ones that carry real traffic. They beat compounds whenever they apply.

A school is a lernejo, not a lernodomo. A teacher is an instruisto, not an instruhomo. Both compounds are comprehensible and both are wrong in the way that learning-building is wrong in English: understandable, and immediately marking you as a foreigner.

Compounding is what you use when the affixes run out. There is no suffix meaning made of iron and none meaning powered by steam, so fervojo and vaporŝipo have to be built the long way.

The two systems also mix freely inside one word, which is where Esperanto vocabulary gets its reputation:

mal- + san- + -ul- + -ej- + -o = malsanulejo, a hospital

Reading a long word: start at the right

That last example is the technique. When you meet a word you have never seen, do not read it left to right. Read it backwards, one morpheme at a time, and let each piece narrow the last:

• malsanulejo: -o it is a noun, -ej- it is a place, -ul- a place for people, san- healthy people, mal- unhealthy people. A hospital.
• lingvoscienco: -o a noun, scienc- a science, lingvo- about language. Linguistics.
• internacia: -a an adjective, naci- nation, inter- between. International, which is where the language's own name comes from.

Do this deliberately a dozen times and it becomes automatic. It is the single highest-return reading habit in Esperanto, because it converts an unknown twelve-letter word into four things you already know.

Where I would not compound

Here is the stylistic side, and I will take a position on it: English speakers over-compound in Esperanto.

Compound when you are naming a type of thing that recurs and deserves its own word. Fervojo, ĉefurbo, libroservo, mondmilito, naskiĝtago. These are categories.

Use a preposition when the relation is a one-off between two particular things:

la libro de mia patro - my father's book

la domo apud la maro - the house by the sea

Patrolibro would technically parse. It would also mean nothing useful, because it names a category of book that does not exist. Compounds are lexical, not syntactic: they make dictionary entries, not sentences.

The other restraint is length. Three roots is fine. Four is getting on. If you are reaching for five, you probably wanted a phrase, and the language permits a hyphen for clarity where a compound gets genuinely hard to parse, which is standard practice with proper names (Esperanto-kongreso).

What to take away

• The last root is the head: vaporŝipo is a ship.
• Only the last root takes the ending, and the compound declines as one word: vaporŝipojn.
• The linking vowel is -o-. Drop it when the join is easy (tagmezo), keep it when it is not (noktomezo).
• Use an affix where one exists; compound only where none does.
• Read long words from the right, morpheme by morpheme.
• Compound to name a category; use a preposition for a one-off relation.