adverb
completely, at all
B1
Gar is an adverb meaning completely, utterly, or (with negation) at all. It intensifies adjectives or negations: gar nicht = not at all. No preposition or reflexive use. Common in phrases: gar so (so very), gar kein, gar nichts. It’s a degree adverb.
Examples
Das Fenster war ganz geschlossen, als ich kam.
The window was completely closed when I arrived.
Ich habe das gar nicht verstanden.
I didn't understand that at all.
Die Maschine funktionierte gar nicht, als der Techniker versuchte, das Problem zu finden.
The machine did not work at all when the technician tried to find the problem.
Details
Mnemonics
Imagine a volume knob turned to maximum — 'gar' intensifies
Think 'gar' ~ English 'gar' in 'gargantuan' (very) to remember intensity
Notes
As an adverb, 'gar' is an intensifier often used in negatives ('gar nicht' = 'not at all') or to mean 'completely' or 'quite'. It is common in spoken and written German.