Double infinitive constructions (with modal verbs or 'lassen') in the perfect tense

Double infinitive constructions in the perfect tense with modal verbs or 'lassen' in German

Short overview

German uses a "double infinitive" whenever a modal verb (können, müssen, dürfen, sollen, wollen, mögen) or the causative verb lassen appears together with another verb in the infinitive and you want to form the perfect (Perfekt) or other compound tenses. Instead of using the modal's past participle, standard German keeps both verbs in the infinitive at the end of the clause, and uses haben (or its past forms) as the auxiliary.

What is the double infinitive?

A double infinitive simply means there are two infinitives together at the end of a clause: the main verb (the action) + the modal (or lassen). Example in the perfect:

- Er hat kommen wollen. — He has wanted to come.
- Wir haben gehen müssen. — We have had to go.
- Sie hat ihn reparieren lassen. — She has had him repair it / She let him repair it.

Instead of a past participle of the modal (gewollt / gemusst / gedurft …) the infinitive is used because the modal governs another verb.

When do I use the double infinitive?

- When a modal verb takes another infinitive and you form the perfect: Ich habe kommen wollen. (not *Ich habe gekommen oder *Ich habe gewollt kommen.)
- When lassen is used causatively (to let/have somebody do something): Sie hat ihn gehen lassen.
- In compound tenses built from haben (Perfekt, Plusquamperfekt, Konjunktiv II Perfekt), and in conditional forms with hätte/hätten, you keep the two infinitives.

Note: If the modal appears without another infinitive (no complement), you form the perfect with the modal's past participle: Er hat das nicht gewollt / Sie hat lange gedurft. But as soon as there is a second verb, the double infinitive pattern is used.

How do I form the perfect with modal verbs (the pattern)?

Formula (Perfekt):

Subject + haben (conjugated) + ... + main-verb-infinitive + modal-infinitive

Examples:

- Ich habe das Buch lesen wollen. — I wanted to read the book. (lit. I have wanted to read the book.)
- Du hast früher gehen müssen. — You had to leave earlier. (lit. You have had to go earlier.)
- Er hat nicht kommen dürfen. — He was not allowed to come. (lit. He has not been allowed to come.)
- Wir haben ihn sehen können. — We were able to see him. / We could see him.

Notes
- Order of the two infinitives: main verb first, modal (or lassen) second: lesen wollen, gehen müssen, helfen lassen.
- Auxiliary: use haben even if the main verb normally takes sein when used alone (see below).

How do I form the perfect with lassen (causative)?

Pattern for causative lassen:

Subject + haben (conjugated) + object (if any) + main-verb-infinitive + lassen

Examples:

- Sie hat ihn das Auto reparieren lassen. — She had him repair the car / She got the car repaired.
- Ich habe mich rasieren lassen. — I had myself shaved / I got a shave.
- Er hat das Regal aufbauen lassen. — He had the shelf assembled / He got the shelf put up.

Contrast with lassen as a single main verb (no following infinitive): then you use gelassen (Partizip II) in the perfect:

- Er hat das Fenster offen gelassen. — He left the window open.

Word order: where do the infinitives, objects and 'nicht' go?

Basic end-cluster

In main clauses the auxiliary (haben) stands in second position and the two infinitives go together at the end:

- Er hat kommen wollen. — He has wanted to come.
- Wir haben bleiben müssen. — We have had to stay.

Objects and pronouns

Objects and pronouns come before the final infinitive cluster:

- Ich habe ihn treffen wollen. — I wanted to meet him.
- Hast du es verstehen können? — Could you understand it?
- Ich habe mich nicht beschweren wollen. — I didn’t want to complain.

Negation — placement of nicht

The particle nicht normally goes before the infinitive cluster (or before the element it negates):

- Ich habe nicht kommen können. — I couldn’t come.
- Ich habe das nicht tun wollen. — I didn’t want to do that.

If you want to negate the modal specifically (shifting emphasis), placement can change slightly, but the usual, clear pattern is as above.

Separable-prefix verbs

Separable verbs keep their full infinitive form (with prefix attached) in the cluster:

- Er hat gestern früh aufstehen müssen. — He had to get up early yesterday.
- Sie hat die Tür abschließen lassen. — She had the door locked.

Auxiliary sein vs. haben

Many verbs of motion or change normally take sein in the perfect: Er ist gegangen / Sie ist gekommen. But when such verbs appear with a modal, standard German uses haben + double infinitive:

- Er ist gestern gegangen. — He went (or has gone) yesterday.
- Er hat gehen müssen. — He had to go. (NOT *Er ist gehen müssen in standard German.)

Colloquial varieties sometimes use sein here (especially in southern German), but in standard written German use haben + double infinitive.

Other tenses and moods with double infinitive

Plusquamperfekt (past perfect)

Use the simple past of haben (hatte/hattest/hatten) + double infinitive:

- Ich hatte kommen wollen. — I had wanted to come.
- Wir hatten gehen müssen. — We had had to go.

Konjunktiv II (conditional) perfect

Use the subjunctive form of haben (hätte/hättest/hätten) + double infinitive:

- Ich hätte dir helfen können. — I could have helped you.
- Er hätte bleiben müssen. — He would have had to stay.

Subordinate clauses (brief note)

In subordinate clauses the finite auxiliary moves to the end of the clause. The double infinitive cluster may therefore appear before the auxiliary. Because these sentences can become heavy, many speakers prefer the preterite (wollte, konnte, musste …) in subordinate clauses.

Example (possible but stylistically heavy):

- Main clause: Er hat kommen wollen. — He has wanted to come.
- Subordinate clause (less common): Ich glaube, dass er kommen wollen hat. — I believe that he has wanted to come.

In normal speech/writing many Germans prefer: Ich glaube, dass er kommen wollte.

Modal participles vs double infinitive — what's the difference?

If the modal has no infinitive complement, use the modal's past participle:

- Ich habe das nicht gewollt. — I did not want that.
- Er hat lange gedurft. — He was allowed for a long time.

But when the modal governs another verb, standard German forms the perfect with the double infinitive (not with the modal participle plus a second infinitive):

- Ich habe das nicht tun wollen. — I didn’t want to do that. (not *Ich habe das nicht gewollt tun.)

Comprehensive set of examples (grouped by use)

Basic modal examples (Perfekt)

- Ich habe kommen wollen. — I wanted to come.
- Er hat bleiben müssen. — He had to stay.
- Wir haben ihn sehen können. — We were able to see him.
- Du hast nicht helfen dürfen. — You were not allowed to help.
- Sie hat das tun sollen. — She was supposed to do that.

Negative forms

- Ich habe nicht kommen können. — I couldn’t come.
- Sie hat das nicht machen wollen. — She didn’t want to do that.
- Wir haben nicht früh gehen dürfen. — We weren’t allowed to leave early.

Questions (Perfekt with modals)

- Hast du das finden können? — Were you able to find that?
- Hat er kommen wollen? — Did he want to come?

Separable verbs

- Er hat gestern früh aufstehen müssen. — He had to get up early yesterday.
- Sie hat das Licht anlassen wollen. — She wanted to leave the light on.

Pronouns / reflexives

- Ich habe ihn treffen wollen. — I wanted to meet him.
- Ich habe mich rasieren lassen. — I had myself shaved.

Lassen (causative) examples

- Sie hat ihn das Auto reparieren lassen. — She had him repair the car.
- Ich habe den Teppich reinigen lassen. — I had the carpet cleaned.
- Er hat mich lange warten lassen. — He made me wait a long time / He let me wait.

Lassen vs. gelassen (contrast)

- Er hat die Tür offen gelassen. — He left the door open. (gelassen = past participle)
- Er hat die Tür offen lassen. — He has left the door open / He let it remain open. (Here the infinitive cluster emphasizes the state or the act of letting; both forms can be used but meanings and emphasis differ slightly.)

Plusquamperfekt / Konjunktiv II examples

- Ich hatte gehen müssen. — I had had to go.
- Ich hätte kommen können. — I could have come.
- Er hätte sie besuchen wollen. — He would have wanted to visit her.

Common mistakes and how to avoid them

- Wrong auxiliary: *Er ist gehen müssen. — Use haben: Er hat gehen müssen.
- Wrong order: *Ich habe wollen kommen. — Correct: Ich habe kommen wollen.
- Trying to use the modal’s participle with another infinitive: *Ich habe das gemacht gewollt. — Correct: Ich habe das nicht tun wollen or Ich habe das nicht gewollt (if no second verb).
- Forgetting object placement: *Hast du verstehen können das? — Correct: Hast du das verstehen können?

Quick reference: formulas and short cheatsheet

- Perfekt with modal: haben + main-infinitive + modal-infinitive. (Ich habe kommen können.)
- Perfekt with lassen (causative): haben + (object) + main-infinitive + lassen. (Sie hat ihn gehen lassen.)
- Plusquamperfekt: hatte + main-infinitive + modal-infinitive. (Ich hatte bleiben müssen.)
- Konjunktiv II perfect: hätte + main-infinitive + modal-infinitive. (Ich hätte dir helfen können.)
- Use haben even if the main verb normally takes sein.
- Main verb comes before modal / lassen in the infinitive cluster.

Short summary

- Double infinitives occur when a modal verb or lassen combines with another infinitive in compound tenses.
- Standard German uses haben + two infinitives (main + modal/ lassen) rather than the modal’s participle.
- Watch the order: main infinitive first, modal (or lassen) second; objects and negation come before the infinitive cluster.
- In subordinate clauses or in speech many speakers prefer the preterite of the modal (wollte/konnte/musste) to avoid heavy double-infinitive constructions.

Glossary

- Infinitive: the basic, unconjugated form of a verb (gehen, kommen, lesen).
- Double infinitive: two infinitives together (main verb + modal or lassen) at the end of a clause.
- Modal verbs: verbs that modify ability, necessity, permission, desire, etc. (können, müssen, dürfen, sollen, wollen, mögen).
- Causative lassen: lassen used to mean "have/let (someone) do something" or "get something done." (die Tür reparieren lassen)
- Auxiliary: the helping verb used to form compound tenses (haben, sein). In double infinitive constructions we normally use haben.
- Partizip II (past participle): e.g., gemacht, gegangen, gelassen. Modals also have participles (gewollt, gemusst), but they are not used with another infinitive in standard double-infinitive perfect forms.

If you want, I can now give more focused examples for a single modal (e.g., all forms of müssen) or show how this pattern behaves inside questions, relative clauses or with separable verbs in more detail.