11
votes
4answers
375 views

Expression for someone with very broad and detailed knowledge

Are there any well-known German expressions for someone who is very board and detailed in knowledge? for example: He is a human database
10
votes
3answers
163 views

Terms for “Nicht-Verstehen signalisieren”

As I read here: The first two sentences are classified as "Nicht-Verstehen signalisieren". Are there other widely known terms or interjections to signal you didn't understand something?