Dutch future perfect and conditional perfect (zal / zou hebben gedaan)

Two Dutch tenses stack three verbs to talk about something being finished at a point that is still ahead. The future perfect says an action will be done by then: Morgen zal ik het rapport hebben afgemaakt. (Tomorrow I will have finished the report.) The conditional perfect does the same for an imagined, contrary-to-fact past: Ik zou het rapport hebben afgemaakt. (I would have finished the report.) Both are the perfect-tense partners of the plain future and the plain conditional.

Both tenses use the same three-part pattern: a form of zullen, then hebben or zijn, then a past participle. The future perfect uses the present of zullen (zal / zult / zullen); the conditional perfect uses its past, zou / zouden.

1. Pick the zullen form. Future perfect: ik zal, jij zult/zal, hij zal, wij/jullie/zij zullen. Conditional perfect: ik/jij/hij zou, wij/jullie/zij zouden.
2. Add the helper of the perfect tense — hebben for most verbs, zijn for movement-to-a-goal and change-of-state verbs. It is the same hebben-or-zijn choice as in the ordinary present perfect: hebben gemaakt but zijn gegaan.
3. Add the past participle at the end: gemaakt, gewerkt, gegaan, begonnen.

In a main clause the zullen form is the second element and the other two verbs drop to the very end, forming a cluster: Om acht uur zal ik mijn werk hebben afgemaakt. (By eight I will have finished my work.) The order inside that cluster is flexible — both hebben afgemaakt and afgemaakt hebben are correct standard Dutch, so Om acht uur zal ik mijn werk afgemaakt hebben is equally fine.

Use zal hebben/zijn + participle for something that will already be completed at a future moment — a result you look back on from a point still ahead.

• A deadline or future point by which the action is done: Voordat je thuis bent, zal de film zijn begonnen. (Before you get home, the film will have started.)
• A confident guess about the present or recent past (a probable conclusion): Hij zal het wel zijn vergeten. (He will have forgotten it, i.e. he has probably forgotten.)
• In everyday Dutch the future perfect is rare. A present perfect with a time word normally carries the same meaning: Tegen vrijdag heb ik alles geregeld (By Friday I will have arranged everything) does the job that Tegen vrijdag zal ik alles hebben geregeld would — both point at the same finished result.

Use zou hebben/zijn + participle for a hypothetical, contrary-to-fact past — what would have happened under conditions that did not come true.

• In the result half of an unreal als (if) sentence: Als ik het had geweten, zou ik je hebben gebeld. (If I had known, I would have called you.) The als-clause takes the pluperfect (had geweten), the result clause the conditional perfect.
• For a regret or a past that did not happen: Zonder de file zou ze op tijd zijn aangekomen. (Without the traffic jam she would have arrived on time.)
• Dutch often replaces it with the plain pluperfect: Als ik het had geweten, had ik je gebeld means exactly the same and is more common in speech.

The hebben/zijn choice is the same trap as in the ordinary perfect, and it is easy to default to hebben. Movement-to-a-goal and change-of-state verbs keep zijn here too: De trein zal zijn vertrokken, not zal hebben vertrokken; Ze zou zijn aangekomen, not zou hebben aangekomen. When unsure, check whether the plain present perfect of the verb would use ben/is — if it does, the future and conditional perfect use zijn as well.