verb
to set, to determine
B1
festlegen: to set or to determine (often transitive). It's a separable verb (imperative: 'leg fest'), regular/weak with perfect participle 'festgelegt' and uses auxiliary haben. Not reflexive. Use it for fixed decisions, deadlines or parameters (e.g., 'Termine festlegen'). Present: ich lege fest; past: ich legte fest.
Examples
Die Regeln wurden klar festgelegt, damit es keine Verwirrung gibt.
The rules were clearly determined so there would be no confusion.
Der Vorstand legte das Datum fest, weil der Termin für alle Abteilungen wichtig war.
The board set the date because the appointment was important for all departments.
Wir legen den Termin fest.
We set the appointment.
Details
Mnemonics
Imagine pinning a sticky note labeled 'SET' onto a calendar date to lock it in place
sounds like 'fast' + 'lay' (fast-lay = set down quickly)
Notes
A separable verb: in main clauses the prefix 'fest' separates and goes to the end (ich lege fest), but in infinitive, participle and subordinate clauses it stays attached (festlegen, festgelegt).