indien means “if (formal)”. Starts a sub-clause and sends its verb to the very end.
Subordinating · Onderschikkend
Indien nodig, bel ik de dokter.
If necessary, I'll call the doctor.
Indien u vragen heeft, mail ons.
If you have questions, email us.
Drag scrambled words into the right Dutch order and master inversion and the verb-final rule.