As the title of this question says, are questions like “I wrote this text in German language … Is it grammatically correct?” on topic for this site?
No, in this broadness such a question would not be on-topic here. We do not offer a proof-reading service, and we strive to discuss questions that would be of interest for a general audience. Your text in whole is likely to be a specific problem of yours that nobody else would stumble upon again.
Your are welcome, however, to specify parts of your text that you suppose to be not correct, say why you chose to write them this way and why you have doubts about them. Ideally, you would pose one question per problem that you identified. This would easily make a good question here, since we can then focus on one specific problem, which is also more likely to be of interest for other visitors of this site.
We do not offer a free peer review service.
Exceptionally we may however give help on a single specific issue that may have occured provided it is of some general interest.
The same criteria as were defined for translation requests hold true:
- Help Center
- How do I ask good, on-topic questions for translations or about differences?
- Is it welcome to answer a simple translation request?
- When is a translation request to German off-topic?
If in doubt you are welcome to ask your fellow users in the German Language Chat to guide you on how to write a good question about your issue.