i wrote "jag flyga" and this was marked wrong, but "flyga" appears under the word when hovering over "fly".. why is this?
Because all translations of a word will show up when you hover. This is not something we can change as moderators and editors, sorry.
"Flyga" is infinitive. The sentence is saying that "I'm am flying right now". "Flyger" is present.
flyga and flyger change tenses when you are doing it now versus just saying "go fly a kite"