adverb
inside, indoors
A2
Drinnen is an adverb meaning 'inside' or 'indoors', used to indicate location within a building or space. It contrasts with draußen. It's not a preposition and doesn't take cases; combine with verbs of position or movement (e.g., 'Bleib drinnen', 'Es ist warm drinnen').
Examples
Weil es plötzlich zu regnen begonnen hatte, blieben die Kinder drinnen, obwohl sie vorher draußen spielen wollten.
Because it had suddenly started to rain, the children stayed inside, although they had wanted to play outside beforehand.
Wir bleiben heute drinnen und lesen ein Buch.
We're staying indoors today and reading a book.
Bleib bitte drinnen, es regnet.
Please stay inside, it's raining.
Details
Mnemonics
imagine being inside a small house labeled 'drinnen'
sounds like 'drin' → think 'in' (inside)