In my German class, I was told that, "Es ist zu tun," can mean either that that it must be done, or that it can be done. "Es muss getan werden" oder, "Es kann getan werden."

Is this really correct? I would have guessed that it is only "müssen" and that the verb "können" would only be used when the sentence is negative, i.e. "Est ist nicht zu tun" = "Es kann nicht getan werden." If my teacher is right, it seems like a problematic ambiguity.

  • "I know what you mean." The ambiguity of "you" representing a single person (singular) or a group (plural) is equally ambiguous and problematic, no? For this there is context.
    – bakunin
    Commented Feb 20 at 21:03
  • 1
    @bakunin You could likewise say that “this” and “that” are ambiguous and depend on context. But these are indicative like pronouns. My complaint is that there is a huge difference between necessity and possibility.
    – mbsq
    Commented Feb 20 at 22:49

3 Answers 3


Ambiguity exists in many languages in many expressions. Most of the time, the ambiguity is resolved by the context. It might be a good idea to avoid such expressions if you want to prevent misunderstanding.

I'm not sure whether your teacher told it exactly like that, but I would avoid this expression for both meanings. But if I heard it in a conversation, I would assume that it refers to something that should be done, unless the topic of the conversation is whether it is possible to do something. Most things are possible with enough effort.

Related note:

People often use expressions that are ambiguous or mean something different than what they want to express. For example "Can you help me?". The literal answer is often "Yes". But most people asking (and answering) will interpret the question as "Will you help me?".


The phrase etw. ist zu tun is typically used in conjunction with the indication of a specific goal. It describes the activity that is required (i.e., must be done) to achieve this goal. Therefore, it is synonymous more to etw. muss getan werden (sth. must be / has to be done) than to etw. kann getan werden (sth. can be done). For example:

  • Der Vertrag ist zu unterzeichnen, um gültig zu sein.
    = Der Vertrag muss unterzeichnet werden, um gültig zu sein.
    (The contract has to be signed in order to be valid.)

  • Was ist noch zu tun, damit die Party endlich losgehen kann?
    = Was muss noch getan werden, damit die Party endlich losgehen kann?
    (What is still to be done to get the party started?)

  • Bevor wir essen können, ist das Geschirr noch abzuwaschen.
    = Bevor wir essen können, muss das Geschirr noch abgewaschen werden.
    (Before we can eat, the dishes have to be washed.)

But notice also that there is the idiom

  • Das ist (nicht) zu machen/schaffen.
    = Das ist (nicht) machbar/umsetzbar/durchführbar.
    (That is (not) feasible/achievable.)
  • 2
    I think the second meaning ("it is (not) possible") exists too, but only in archaic usage. Compare with "Es ist (nicht) zu schaffen."
    – AEF
    Commented Feb 20 at 12:17
  • 2
    See "Das ist zu machen" -> "das ist machbar"
    – tofro
    Commented Feb 20 at 12:36
  • @tofro, you are right. I have updated the answer accordingly. Commented Feb 20 at 13:50
  • @AEF, you are right. I have updated the answer accordingly. Commented Feb 20 at 13:51

Both meanings are attested by dictionaries, e.g. DWDS:

Grammatik: entspricht einem mit »können« umschriebenen Passiv
diese Frage ist leicht zu beantworten

Grammatik: entspricht einem mit »müssen« umschriebenen Passiv
der Ausweis ist am Eingang vorzuzeigen (= muß vorgezeigt werden)

Both meanings are briefly mentioned in the Duden grammar (8th/9th ed. § 805, p. 549/562; 10th ed., § 622, p. 386) and Hammer's German Grammar (7th. ed, section 13.4.5(a), p. 339).

The ambiguity is usually not a problem. The meaning of the infinitive helps. For instance, sehen in its literal meaning is highly compatible with possibility:

Oft ist der Gipfel zu sehen.
Auf den Aufnahmen waren zwei Männer zu sehen.

On the other hand, sehen in the meaning of bewerten, einschätzen is compatible with necessity:

Teilhabe und Austausch sind positiv zu sehen.
Die Probleme sind vor diesem Hintergrund zu sehen.

Adverbials also help.

Das ist schnellstens zu erledigen. (müssen)
Das ist ohne Probleme zu erledigen. (können)

I checked the examples I gave with DeepL and Google Translate; both tools chose the same interpretation I did, which I take as an indication that the rest of the sentence contains enough information to make a good guess at the meaning.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.