We rely on written language to develop software. I used to joke that I worked as a professional email writer rather than a computer programmer (and it wasn’t really a joke). So if you want to be a better engineer, I recommend that you focus some time on improving your written English.
I recently bought 100 Ways to Improve Your Writing by Gary Provost, which is a compact and rewarding book full of simple and widely applicable guidelines to writers. My advice is to buy a copy!
You can also find plenty of resources online. Start by improving your commit messages. Since we love to automate things, try these shell scripts that catch common writing mistakes. And every time you write a paragraph simply ask yourself: what is the purpose of this paragraph? Is it serving that purpose?
Native speakers and non-native speakers will both find useful advice in Gary Provost’s book. In the UK school system we aren’t taught this stuff particularly well. Many English-as-a-second-language courses don’t teach how to write on a “macro” level either, which is sad because there are many differences from language to language that non-natives need to be aware of. I have seen “Business English” courses that focus on clear and convincing communication, so you may want to look into one of those if you want more than just a book.
Code gets read more than it gets written, so it’s worth taking extra time so that it’s easy for future developers to read. The same is true of emails that you write to project mailing lists. If you want to make a positive change to development of your project, don’t just focus on the code — see if you can find 3 ways to improve the clarity of your writing.