Du schreibst sehr gut
"Very good" in English is "sehr gut" in German.
sehr gut
sehr sehr gut
"Very good song" translated into German is "Sehr gutes Lied".
Very good story = sehr gute Geschichte
The German word for write is schreiben.
Das war sehr gut
das ist sehr gute
You say "verfassen".
Sie ist sehr gut is the translation in German. It is translated from English to German. German is mostly spoken in the European countries.
You say "zurückschreiben".
In what language please? If you were to ask for German it would be "Serh Gute"!