This is an excellent use case. It made learning German much easier. I write what I think is correct, then get a fixed version.

When writing in English though, I use it more like a dictionary. If you want to write past a certain level, an LLM works better as a metaphor and idiom search engine.

I also like to ask it to generate 20 ways to say the same thing. It’s a great way to simplify or smoothen sentences without losing your voice.