verb
to serve
B1
dienen means to serve (to be of service). Regular weak verb; auxiliary 'haben'; participle gedient. Not reflexive. Takes dative objects (jemandem dienen) and is used with als (dienen als) or zu+Inf to indicate purpose. Common in formal contexts; conjugates regularly.
Examples
Der alte Brunnen diente als Treffpunkt, obwohl er schon lange repariert werden musste, sodass die Stadt schließlich Handwerker beauftragte.
The old fountain served as a meeting place, although it had needed repairs for a long time, so the city finally hired craftsmen.
Das hat einem guten Zweck gedient.
That served a good cause.
Er diente seinem Land.
He served his country.
Details
Mnemonics
Picture someone handing out plates at a dinner, always 'serving' others.
Sounds like 'dean' — imagine a dean serving the students.
Notes
Dienen is generally transitive/intransitive depending on context ('jemandem dienen' = to serve someone). In formal contexts it can mean service to a cause or institution. Passive voice is not applicable because 'dienen' is generally intransitive (takes a dative) and does not form a usual passive.