preposition
over, above, about
A1
Über: a two-way preposition meaning 'over'/'above' (position or movement) and 'about' (concerning). Use accusative for movement/direction (Wohin?) and for 'about'; use dative for static location (Wo?). Governs accusative or dative depending on context; common and highly frequent. Also appears in many idioms and as prefix in separable verbs.
Examples
Die Diskussion über die neuen Regeln dauerte lange, weil die Teilnehmer verschiedene Vorschläge machten.
The discussion about the new rules lasted a long time because the participants made different proposals.
Der Ball flog über das Dach.
The ball flew over the roof.
Wir sprechen über das Problem.
We're talking about the problem.
Details
Mnemonics
Picture a bridge 'über' a river — 'über' = over/above; for 'about' think of a book about a topic with the title 'Über...'.
Notes
A two-way preposition in location vs. movement contexts (and commonly used with accusative to mean 'about' when discussing topics).