adverb
against that, on the other hand
A2
dagegen: adverb meaning 'against that' or 'on the other hand', used to express opposition or contrast. Often used with verbs like sein (Ich bin dagegen = I'm against it). It's a da‑compound replacing 'gegen das', not inflected. Opposite: dafür; also common in contrastive sentences.
Examples
Einige Fachleute lobten das Konzept, andere waren dagegen, weil die Kosten stiegen.
Some experts praised the concept, others were against it because the costs rose.
Viele sind dafür, aber einige sind dagegen.
Many are in favor, but some are against it.
Das alte System hatte Vorteile, dagegen war das neue schneller.
The old system had advantages; on the other hand, the new one was faster.
Details
Mnemonics
picture two arrows pointing opposite directions; one labeled 'dafür', the other 'dagegen'
sounds like 'day-gain' — imagine someone arguing against an idea to 'gain' their point
Notes
Often used to express opposition or contrast. Can replace 'gegen das' or refer back to a previous statement.