Learn Hardcore Dutch: De opdracht is pas volledig als alle apparatuur schoon is. - The assignment is only complete when all equipment is clean.

Here pas functions as an adverb meaning “only” or “not until.” So De opdracht is pas volledig… literally means “The assignment is not complete until…” or “The assignment is only complete when…” It emphasizes that you can’t consider it done before the equipment is clean.

Why is volledig used instead of klaar?

Both volledig and klaar can convey that something is finished, but there’s a subtle difference. Volledig means “complete” in the sense that every part has been done, while klaar is more like “ready” or “finished.” You could say De opdracht is pas klaar als…, but using volledig stresses that absolutely every step must be done (including cleaning).

Why is als used here, and could we use wanneer instead?

In Dutch, als often introduces conditional or time clauses (“if/when”). Here it means “when.” You could replace it with wanneer (“when”) without changing the meaning:
De opdracht is pas volledig wanneer alle apparatuur schoon is.
als is more conversational; wanneer is slightly more formal or explicit for “when.”

Why is the verb placed at the end in …alle apparatuur schoon is?

This is a subordinate clause. In Dutch subordinate clauses (introduced by words like als, omdat, terwijl, etc.), the conjugated verb moves to the end. That’s why you get apparatuur schoon is instead of is schoon apparatuur.

Why is there no article before apparatuur?

Apparatuur is an uncountable (mass) noun in Dutch, similar to “equipment” in English. You don’t normally use de or het when speaking about equipment in general. Saying alle apparatuur covers “all equipment” as a whole.

Why alle apparatuur and not alle de apparatuur or alle apparaten?

alle apparatuur treats equipment as one collective concept, so no article is needed.
alle de apparatuur is less common; you’d only add de if you’re referring to a specific set you already introduced.
alle apparaten would mean “all individual devices/apparatuses,” focusing on countable items. Use that if you really mean “all the machines” rather than “all the equipment.”

Why is schoon not inflected as schone?

In predicative position (after a form of zijn, i.e. “to be”), adjectives in Dutch stay in their base form. You say de apparatuur is schoon, not de apparatuur is schone. Only attributive adjectives (before a noun) get an ending: schone apparatuur (clean equipment).

Could we replace pas with alleen, or move it elsewhere in the sentence? Where do adverbs like pas go?

alleen can sometimes mean “only,” but De opdracht is alleen volledig… sounds slightly off; Dutch prefers pas volledig for “only then complete.”
Adverbs in Dutch usually come after the finite verb in main clauses: De opdracht is pas volledig… Moving pas elsewhere can change emphasis or sound awkward:
- Pas is de opdracht volledig als… (rare and marked)
- De opdracht is volledig pas als… (ungrammatical)
  So the most natural spot is right before the adjective volledig here.