particle
un- (negation prefix), not / non-
B1
un- is the German negation prefix meaning un-/not/non-, forming opposites (unwichtig, unklar). A derivational, inseparable particle attached to adjectives and some nouns; it does not negate verbs like 'nicht'. No auxiliary issues. Meaning can vary by base word and sometimes creates different semantic shades.
Examples
Weil das Präfix 'un-' die Bedeutung vieler Wörter veränderte, erklärten die Lehrkräfte die Regeln, als die Schüler Schwierigkeiten hatten.
Because the prefix 'un-' changed the meaning of many words, the teachers explained the rules when the students had difficulties.
Das Präfix un- macht aus 'bekannt' das Gegenteil: 'unbekannt'.
The prefix un- creates the opposite: 'bekannt' becomes 'unbekannt' (unknown).
Viele Adjektive bekommen mit un- eine Negation, zum Beispiel 'unglücklich' oder 'unwichtig'.
Many adjectives take un- to form a negation, for example 'unglücklich' or 'unwichtig'.
Details
Mnemonics
Imagine placing a red 'NOT' stamp in front of a word, turning 'happy' into 'not happy' = 'unhappy'.
Same as English 'un-' meaning 'not' — sounds identical.
Notes
The prefix un- is a productive negation in German, similar to English. It attaches directly to adjectives and some nouns/verbs to create opposites.