noun
Sunday
A1
“Sonntag” means Sunday, the day of the week. Masculine noun (der Sonntag) with plural Sonntage. Common uses: a specific Sunday (am Sonntag) or recurring Sundays (an Sonntagen). Declension is regular; genitive often des Sonntags. Also capitalized like all German nouns and used in calendars and schedules.
Examples
Am Sonntag schlafe ich gerne lange aus.
On Sundays I like to sleep in.
Der Zug fuhr nicht, weil am Sonntag Bauarbeiten durchgeführt wurden, die Verzögerungen verursachten.
The train did not run because construction work was carried out on Sunday, which caused delays.
Am Sonntag besuche ich meine Familie.
On Sunday I visit my family.
Details
Mnemonics
Picture a lazy sunny Sunday with people relaxing
sonn + tag (sun + day) matches English Sunday
der = imagine a man relaxing on Sunday
Notes
Sonntag is the German word for Sunday and is masculine.