I'm currently grappling with understanding the usage of Ersatzinfinitiv, particularly in combination with modal verbs (such as "können," "müssen," "wollen," etc.) and the perfect tense. I find it challenging to discern when and how to use it correctly, especially in complex sentences.

Furthermore, I'm struggling to differentiate between when to use the Ersatzinfinitiv versus the regular participle form in various contexts.

I apologize if this request seems extensive, but any guidance or insights you can offer would be greatly appreciated.

1 Answer 1


My personal recommendation for understanding what grammar books call "Ersatzinfinitiv" goes like this:

First you understand that some verbs can (and most often will) be used in a "modal form". A modal usage of the verb means that the conjugated verb comes with an infinitive of another verb. This is similar to English:

Modal use:

Ich kann dieses Gericht essen (I can eat this dish).

Ich will das sehen (I want to see this).

(Note that in English, you have here a modal use with "can", but with "want", you don't have a plain infinitive, but an "infinitive group", "to see").

Non-modal use:

Ich kann diese Aufgabe nicht! (Meaning: This task is too difficult for me!)

Ich will mehr Wein! (I want more wine!)

Now when we change the tense, only the conjugated verb changes. If it is used modally, the infinitive to it does not change.

Ich konnte dieses Gericht nicht essen.

Ich wollte das sehen.

Ich konnte diese Aufgabe nicht!

Ich wollte mehr Wein.

Things get funny (and here we come to the Ersatzinfinitiv) if we put the stuff into the past tense. You know that the past tense is constructed using an auxiliary verb (haben/sein), and the PP (Partizip Perfekt). This is basically correct as long as the verb is NOT used in modal form. In a modal use, the PP has the exact shape of an infinitive.

Hence, if you have the non-modal use

Ich kann diese Aufgabe nicht.

and put it into perfect tense, it looks quite normal:

Ich habe diese Aufgabe nicht gekonnt.

But if you have a modal use, the PP now looks like the infinitive, hence "gekonnt" must be replaced by "können":

Ich habe dieses Gericht nicht essen können.


Ich habe mehr Wein gewollt.


Ich habe das sehen wollen.

This use of "wollen" is called "Ersatzinfinitiv", but I think you have an easier life if you remember that in modal context, the PP simply looks like the infinitive.

  • 1
    I think you should mention that the Ersatzinfinitiv is not limited to modal verbs only, but can be constructed with some more verbs.
    – tofro
    Feb 27 at 17:24
  • @tofro : I think this is covered by saying "modal use of the verbs". Or did you have something else in mind? Could you provide an example? Feb 28 at 9:23
  • "Ich habe dich schwimmen sehen" doesn't look to me like a "modal use of the verb" sehen, but it is still valid. The Ersatzinfinitiv can be constructed with "brauchen", "heißen", "lassen", "sehen", "hören", "fühlen", "helfen", apart from modal verbs.
    – tofro
    Feb 28 at 9:28
  • @tofro : It is a modal use. Present tense: "Ich sehe dich schwimmen". Same for "lassen", "hören", "fühlen" and "helfen". I don't see a use for "heißen" here, and I'm not sure whether "brauchen" in modal use isn't just sloppy language: "Ich brauche das nicht wissen" would be better expressed as "Ich brauche das nicht zu wissen". BTW, exactly because of these cases, I used the term "modal use of verbs", and not "modal verbs". A "modal verb" is a verb where the predominate (or in the case of "müssen": the only) use is with a modal form. Feb 28 at 9:31
  • 1
    I don't see anything modal in "Ich sehe dich und du schwimmst". I also don't see anything modal in "ich heiße dich kommen" as in "ich befehle dir, zu kommen".
    – tofro
    Feb 28 at 10:17

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