I have been leading an online writing course for Indonesians since 2009. The most case I found from the students was about using properly grammar. I think every writing workshop has the same issue. I still remember when the first time joining the online writing group where the members can give their reviews each other. As English is my second language, I had many inputs and learned a lot from them. It improved my English in writing. For an example I wrote I go to upstairs. It should be written I go upstairs.
Writing is an interesting activity. Several hours ago I gave a suggestion to a friend to take writing course to learn about the writing technique as I pushed him to write a book that he asked me to write about. He took my suggestion and understood how important to know the basic knowledge of writing including grammar. Yes, grammar is very important. People can judge you from your writing, not based on your race, gender or even your education.
Other interesting issue is about the perception how the readers think after they read our writing. Speaking about this case, I have an interesting story regarding my experience when the first time dealing with a professional copy editor for my first novel, Enthusiasm. The last word in the third paragraph on the Preface page written master but when I got the result of her correction, she offered me another word: muster. Both of these words could be used in that sentence but the problem was we both had different perception. Of course I refused her offering and kept master as the last word in my Preface page as you can see and read it at this link.
What's about you? Do you still need to improve your grammar knowledge for your writing journey or you are one of the professionals in the writing field who always deals with the author scripts? Whoever you are, if you like writing, don't forget to check your grammar before you deliver your writing to your readers. (Well, this will remind me too)
Author of Enthusiasm
"Nothing great was ever achieved without enthusiasm." (RWE)