-end-: Obligation Requiring An Action

The suffix -end- describes something that must undergo an action: pagi “pay” gives pagenda “having to be paid,” and respondi “answer” gives respondenda “requiring an answer.” The action is both necessary and passive. A pagenda fakturo is not a bill that must act; it is the bill on which somebody must perform the act of paying.

English often uses “to be done,” “due,” or “requiring X,” and can leave the responsible person unstated. Esperanto does the same economically with -end-, but only when the base verb can take an object. This restriction follows directly from the suffix's passive logic.

Form and passive necessity

Put -end- after a transitive action base and before the grammatical ending. The adjective in -enda is by far the most useful form:

The suffix is the semantic head “required to be acted upon.” The base contributes the action, and the noun described by the adjective corresponds to that action's object.

Because demandoj is plural, predicative respondendaj agrees in number. It would also take -n where ordinary adjective agreement requires it. The affix changes the lexical meaning, not Esperanto's normal adjective grammar.

The object, not the obligated person, is described

Compare two perspectives on the same duty:

The first sentence names the obligated agent, mi. The second presents the affected object, la mesaĝo, as requiring action and leaves the agent open. This makes -end- useful in instructions, task lists, official notices, and (formal) administrative prose.

What -end- leaves unspecified

The suffix does not by itself identify who must act, why the action is required, or when it must happen. Those details come from context or explicit phrases. An agent can be added with de, and a deadline with an ordinary time expression.

The obligation may come from law, agreement, practical necessity, or the speaker's judgment; -end- does not encode the source. If that distinction matters, state it: laŭ la kontrakto pagenda “payable under the contract,” pro sekureco anstataŭigenda “requiring replacement for safety reasons.”

This economy explains why the form suits labels and lists, but a full clause is often clearer in conversation.

It does not normally attach to an intransitive verb. Iri has no direct object that could “be gone,” so English “I am to go” cannot be copied as mi estas irenda. Say mi devas iri.

The exchange separates an agent's obligation (devas ĉeesti) from an object's required treatment (formularo estas sendenda).

-enda, -ebla, and -inda

Three suffixes can follow the same transitive base while answering different questions:

This minimal contrast is intentionally blunt: practical possibility, positive evaluation, and obligation are independent. English “must-read” can be ambiguous between genuine requirement and enthusiastic recommendation. Esperanto normally distinguishes leginda “worth reading” from structurally possible leg-end-a “required to be read.” In unsegmented writing, however, legenda is also the common adjective “legendary,” built from legend-o. When context cannot disambiguate the two analyses, use the clear paraphrase devas esti legata.

Time, plans, and obligation are different

The future passive participle -ota predicts or plans an action; -enda requires it. Something may be planned without being obligatory, or obligatory without yet being scheduled.

Standalone month names follow this guide's capitalized house style. More importantly, riparota concerns the expected future event, while riparenda evaluates the action as necessary.

That sentence uses subskribota, not subskribenda, because it states a plan rather than a duty.

Scope in longer words

The action immediately before -end- is the action required. Prefixes and earlier affixes therefore belong inside its scope:

• re-leg-end-a → relegenda, required to be read again
• ĝis-dat-ig-end-a → ĝisdatigenda, required to be updated
• pri-pens-end-a → pripensenda, requiring consideration

In ĝisdatigenda, -ig- first creates the transitive action ĝisdatigi “update something”; -end- then marks its object as requiring that action. Removing or moving an element changes the action and therefore the scope.

English noun strings can tempt learners to place material in the wrong order. Build from the verbal paraphrase instead: dokumento, kiun oni devas ĝisdatigi → ĝisdatigenda dokumento. See affix stacking and scope.

Status, frequency, and idiomatic restraint

-end- is official but not part of the original Fundamento: the Academy officially added it in 1953. PMEG describes it as relatively rare. The common forms pagenda, farenda, respondenda, and solvenda are readily understandable, especially in written task-oriented contexts, but long spontaneous formations can sound bureaucratic.

The standalone forms enda “necessary,” ende “necessarily,” and impersonal endas “it is necessary” are regular but rare. Label them (formal, uncommon) and do not assume every listener will process them as quickly as necesa, nepre, or estas necese.

In everyday speech, a clause with devas is often easier to process than a heavily derived adjective. The shorter word is not automatically the simpler message.

This neutral version is pedagogically preferable to (formal, uncommon) Endas, ke vi venu. Productive word formation offers a choice; it does not make the shortest form the clearest one.

Common Mistakes

1. Attaching -end- to an intransitive verb.

2. Confusing necessity with possibility.

3. Confusing obligation with recommendation.

4. Ignoring the passive perspective.

Key Takeaways

• -end- means that the referent must undergo the action named by a transitive base.
• Use devi + infinitive when naming the obligated agent or with an intransitive action.
• Distinguish legebla “readable,” leginda “worth reading,” and legenda “required reading.”
• Affix order identifies the exact required action: relegenda, ĝisdatigenda.
• The suffix is official but relatively uncommon; prefer a clear paraphrase when a novel form becomes heavy.