Questions & Answers about Jeg reagerer roligt, når nogen afbryder mig.
Because the verb at reagere belongs to a very common Danish pattern where the present tense ends in -r.
- at reagere = to react
- jeg reagerer = I react / I am reacting
This is normal in Danish:
- jeg taler = I speak
- jeg bor = I live
- jeg arbejder = I work
So reagerer is simply the present tense form.
Roligt means calmly here.
It comes from the adjective rolig, which means calm. In this sentence, it is being used like an adverb, describing how the person reacts.
- rolig = calm
- roligt = calmly / in a calm way
Danish often uses the -t form of an adjective when it functions adverbially:
- han taler højt = he speaks loudly
- hun arbejder hurtigt = she works quickly
- jeg reagerer roligt = I react calmly
So the -t is not random; it is the normal form used here.