Subordinate clauses in Dutch send all verbs to the end of the clause, creating a verb cluster. A simple case: omdat hij werkt. With an auxiliary: omdat hij heeft gewerkt — auxiliary plus participle. With a modal: omdat hij moet werken — modal plus infinitive. With a modal in the perfect: omdat hij heeft kunnen werken — auxiliary plus modal infinitive plus main infinitive. The subject comes after the conjunction and the entire verb cluster comes last.
When multiple auxiliaries stack up, the ordering within the cluster follows rules that vary between formal writing and everyday speech. In writing the finite auxiliary often comes last: omdat hij gisteren niet heeft kunnen komen. In speech, the finite verb often comes first in the cluster. Native speakers themselves vary, and regional differences between North and South as well as formal versus informal registers create additional variation that learners should simply accept.
The most practically important sequences to learn: hebben or zijn plus past participle (perfect), modal plus infinitive, modal plus hebben or zijn plus infinitive (double infinitive in perfect), worden plus past participle (passive), modal plus worden plus past participle (modal passive). Reading Dutch newspapers and academic texts builds intuition for these clusters. Attempting to consciously calculate the order slows production — aim for absorbed pattern recognition through extensive input.