The exercise itself is in German; the explanation pages it links to are in Turkish.
Stilebenen: gehoben, standard, umgangssprachlich (registers)
The same meaning comes in three registers: speisen–essen–futtern. The dictionary label geh./ugs./salopp tells you which word belongs in which text. Choose the right register in the exercise. All exercise content is in German.
Recognise: match the word labelled ugs. or geh. in the dictionary with its standard equivalent. The label tells you which kind of text the word belongs in.
Matched: 0 / 10German Registers Exercise (C2)
At C2 it is not enough to know a word; you need to know which text it belongs in. This exercise compares four registers: gehoben, standardsprachlich, umgangssprachlich and salopp. Sets of three such as kriegen–bekommen–erhalten or futtern–essen–speisen show in concrete terms what the dictionary labels geh. and ugs. are for.
In written exams, consistency of register is assessed as a separate criterion: a letter that opens with a formal greeting and continues with an everyday verb loses marks. The instant feedback in the exercise shows, sentence by sentence, which choice is out of place and why.
Related (in Turkish): Stilebenen lesson · Modal particles · C1–C2 word list · Placement test
Quick answer
What is in the "Stilebenen" exercise?
The "Stilebenen" exercise is at level C2 and has 5 steps with 50 questions in total: 10 matching items, 30 multiple-choice questions and 10 gap-fill items.
The steps in order: Match · Word choice · Sentence & tone · Richtig/Falsch · Write.
You get instant feedback after every answer; the exercise runs in your browser, is free and needs no sign-up or installation.
Where can I study "Stilebenen"?
The explanation for this exercise is on the page German Registers – Stilebenen: gehoben, standard, umgangssprachlich (C2) (in Turkish). Read the rule there, then reinforce it with the 50 questions on this page.