Inversion in Dutch occurs whenever something other than the subject occupies the first position in a main clause. This is a direct consequence of the V2 rule. Common triggers: adverbs of time or place fronted for emphasis (Gisteren zag ik hem), adverbial clauses fronted before the main clause (Omdat het regende, bleven we binnen), direct objects fronted for contrast (Dat weet ik niet) and connecting adverbs starting a new sentence (Dus gaan we.).
Questions always trigger inversion: Heb jij het gedaan? Waar gaan jullie heen? In commands, the verb comes first with the subject optionally omitted: Ga weg! Kom hier! Inversion also occurs in conditional clauses without als: Had ik het geweten, had ik geholpen. This stylistic construction places the conditional verb first and omits als entirely, and it is common in formal and literary Dutch.
A critical nuance: the coordinating conjunction en does not trigger inversion. En hij werkte de hele dag is correct — not En werkte hij de hele dag. Similarly, maar, of and want generally do not force inversion. Distinguishing coordinating from subordinating conjunctions is therefore essential for getting word order right in complex sentences involving multiple clauses.