Questions & Answers about Ik ga naar de markt om melk te kopen.
They work together to introduce a purpose clause. The basic pattern is:
• om = “in order”
• te = marker for the infinitive verb
So om + [object] + te + [infinitive] means “in order to …”
• naar expresses motion toward a place (“to the market”).
• in de markt or op de markt would mean “inside the market” or “at/on the market” (a location), not movement.