B1
Conjunctional adverbs
deshalb/deswegen/darum (therefore), trotzdem (nevertheless), außerdem (besides), dann/danach (then). These are adverbs and take first position, so the verb comes right after (subject–verb inversion).
Examples
Es regnet, deshalb bleibe ich zu Hause.
It's raining, so I'm staying home.
Er war krank, trotzdem kam er zur Arbeit.
He was sick; nevertheless he came to work.
Das Hotel ist teuer, außerdem ist es laut.
The hotel is expensive; besides, it's loud.
Wir aßen zu Abend, danach gingen wir spazieren.
We had dinner, then we went for a walk.