Transitivity: Which Verbs Take an Object, and What to Do When They Do Not

Here is a sentence that is wrong, and a sentence that is wrong for the opposite reason:

Mi bolas la akvon.

Mi plaĉas la libron.

The first says roughly I am boiling, the water. The second says I please the book. Both are built exactly the way the English is built, and that is the whole problem: English lets almost any verb take an object or not take one as the sentence requires, and Esperanto does not let a single one.

The -ig- and -iĝ- article introduces the machinery that crosses the fence. This one is about the fence: where it runs, which verbs sit on which side, the verbs that straddle it legitimately, and the ones that look as though they take an object and never will.

The rule in one line

Every Esperanto root verb is transitive or intransitive, permanently.

A transitive verb takes a direct object wearing the accusative -n. An intransitive verb takes none, ever, in any sentence, in any tense, no matter how much the English wants one. The class belongs to the root, not to the sentence, and nothing you do changes it. What you can do is build a different verb from the same root with a suffix, which is not a change of class but a new word that happens to share a stem.

That is a genuinely different arrangement from English, and worth a moment before we get to the lists. English verbs have no class. Burn is whatever the sentence needs: the house burns, I burn the letter. Break likewise, and stop, move, grow, open, begin, finish, sink, wake. A native English speaker has never once had to know which of those is which, because the answer has never come up.

In Esperanto it comes up in your first paragraph.

The pairs where English has one word and Esperanto has two

This is the list that costs learners marks, so here it is properly, with the plain root in bold so you can see that the fence does not run the same way twice.

Read the bold column downwards and the point makes itself: the first seven roots are intransitive and their transitive partners are built, the rest are transitive and their intransitive partners are built. There is no principle underneath that, no ending that tells you, no semantic family that predicts it. It is vocabulary.

The consolation is that it is small vocabulary and it is permanent. Learn which side komenci sits on and you have learned it for komencis, komencos, komencinta, komencado and every other thing the root will ever do. Compare that with the English irregular verb list, which you also had to learn and which pays a far worse rate of interest.

La domo brulas. - The house is burning.

La knabo bruligas la paperon. - The boy is burning the paper.

La tago komenciĝas. - The day begins.

Mi komencas la laboron. - I begin the work.

The traps inside the traps

Droni kills the wrong person. Droni is intransitive: it is what the drowning man does. Dronigi is what somebody does to him. English he drowned is ambiguous between the two and English speakers import the ambiguity, with results that are usually comic and occasionally a confession.

La knabo dronis. - The boy drowned. (He died.)

La viro dronigis la katon. - The man drowned the cat. (He killed it.)

A transitive verb without an object is still transitive. Mi manĝas is a complete and correct sentence: manĝi is transitive, and you have simply not said what you are eating. The same goes for mi legas, li kantas, ŝi ludas. Leaving the object unsaid is not the same thing as the verb not having one, and it does not license mi haltas la aŭton, because halti has no object to leave out in the first place.

Komenci is transitive but komenciĝi is everywhere. Both members of a pair are ordinary words in constant use, and neither is the poor relation. The derived one is not a workaround; komenciĝi is simply how you say it begins.

The helpi class: object or preposition, both correct

There is a short list of verbs that genuinely take either a direct object or a preposition, and where the honest answer to which is right is both.

Mi helpas lin. - I help him.

Mi helpas al li. - I help him.

Both have been standard since Zamenhof, who used both. PMEG records the pair and declines to rank them, which is the correct call: there is no evidence that one is better Esperanto and a good deal of evidence that both are used by people who write the language well. The same double life belongs to obei (obei la leĝon or obei al la leĝo) and to pardoni, where the object may be the offence or the offender.

Two pieces of advice, and they pull in opposite directions, which is why both are worth saying.

Pick one and be consistent inside a text. Freedom exercised at random reads as uncertainty. If you write helpi al in your first paragraph, write it in your last.

Do not generalise from this list. It is short and closed. The fact that helpi takes either does not mean plaĉi does, and the next section is entirely about why.

The verbs that look transitive and are not

Here is where English speakers do the most damage, because the English translation puts the person in the subject slot and Esperanto puts the thing there.

Plaĉi does not mean to like. It means to be pleasing.

La libro plaĉas al mi. - The book pleases me, i.e. I like the book.

The book is the subject. You are not the subject, and you are certainly not the object, because plaĉi has none. Mi plaĉas la libron claims that you are pleasing to the book, which is a sentence about a book with opinions.

The same shape runs through a set worth learning as a set:

Note the last two, which are there deliberately. Ĝeni and interesi are transitive and take a plain object, so the set is not all verbs about feelings put the person after al. It is a specific list, and plaĉi and manki are its two most common members by a distance.

If you want the person in the subject slot with an ordinary object, the language has words for that: ŝati for liking, bezoni for needing.

Mi ŝatas la libron. - I like the book.

Mi bezonas monon. - I need money.

Both are perfectly good Esperanto, both are transitive, and no learner has ever got into trouble with either. Plaĉi is worth mastering anyway, because it is common, because it is the more idiomatic way to say some of what English says with like, and because it is on every examiner's list.

Never two accusatives

One verb, at most one object. This is not a stylistic preference, it is a hard rule of the grammar, and it is the reason instrui works the way it does.

English says teach the children Esperanto and give me a book, packing two participants into two bare noun phrases. Esperanto puts one of them into a preposition, and the preposition is almost always al:

Mi instruas la lingvon al la infanoj. - I teach the children the language.

Li donis libron al mi. - He gave me a book.

Ŝi montris la domon al ni. - She showed us the house.

Mi instruas la infanojn la lingvon is not a sentence. Neither is li donis min libron, which promotes you to merchandise.

The near miss to be aware of: a sentence can perfectly well contain a second -n that is not an object. Direction takes -n (li iris en la domon), and so do measures of time and extent (li laboris la tutan tagon, ŝi atendis du horojn). Those are covered in the accusative article and in tricky prepositions; the point here is that they are adverbial, not objects, so they never collide with the one object a transitive verb is allowed.

Reading a dictionary entry

All of this is a lookup problem, so it is worth ninety seconds on how to do the lookup.

Open the Reta Vortaro, or PIV, or any printed dictionary worth the shelf space, and a verb entry carries a class mark next to the headword. The two you will see are:

• tr - transitiva. Takes a direct object.
• ntr - netransitiva. Does not.

Some dictionaries write (tr) and (ntr), some use vt and vi on the Latin-dictionary pattern, and PIV occasionally writes the class out in full. They all mean the same two things.

What the mark buys you is bigger than it looks, because it also tells you the shape of the derived verb you will need later:

• A root marked tr gives you the intransitive free, with -iĝ-: fermi -> fermiĝi.
• A root marked ntr gives you the transitive free, with -ig-: halti -> haltigi.

And if the entry has no mark at all, which happens in small bilingual dictionaries and in most phone apps, read the example sentence instead. Look for a noun wearing -n in the verb's own clause. If one is there, the verb is transitive. If the sentence's subject is doing the thing to itself, or the thing is simply happening, it is not.

The honest caveat, since this article is about being precise: PMEG notes a handful of roots where good writers have genuinely disagreed about the class, usually because the root arrived in the language from a source language that used it both ways. They are rare, you will not meet them for years, and the safe move is the same one as always. Write the -ig- or the -iĝ- explicitly and nobody can mark you wrong.

What to take away

• Every root is transitive or intransitive permanently. The sentence does not get a vote.
• English is no guide, because English verbs have no class at all.
• The pairs to learn: bruli/bruligi, halti/haltigi, droni/dronigi, kreski/kreskigi, daŭri/daŭrigi on the intransitive-root side; komenci/komenciĝi, fini/finiĝi, rompi/rompiĝi, movi/moviĝi, veki/vekiĝi on the transitive-root side.
• A transitive verb with its object left unsaid is still transitive. Mi manĝas is fine; mi haltas la aŭton is not.
• Helpi, obei and pardoni take either an object or al, both standard. The list is short and does not generalise.
• Plaĉi, manki, sufiĉi, aparteni, okazi and ŝajni never take an object: la libro plaĉas al mi, al mi mankas mono.
• No verb takes two accusatives. Instrui ion al iu, doni ion al iu. A second -n in the sentence is direction, time or measure, not an object.
• Dictionaries mark it tr or ntr, and that mark also hands you the derived form: tr plus -iĝ-, ntr plus -ig-.

See also

• Making and becoming: -ig- and -iĝ- - the machinery that crosses the fence this article maps.
• The accusative - what an object actually is, and the direction and measure uses that are not objects.
• The passive - only transitive verbs have one, which is transitivity's other big consequence.
• Participles - -ata against -anta, a distinction that only exists because transitivity does.
• Participles as people and things - what the participles become once they take -o and -aĵ-.
• Tricky prepositions - al and the rest of the set the reversing verbs lean on.
• Word building - the affix system -ig- and -iĝ- belong to.
• Verb tenses - the endings that ride on every root, whichever side of the fence it sits.