I feel that I lose variety of vocabulary and use the same words over and over to explain my thoughts either in verbal or written speech. (especially in business emails). It is not that bad, but doesn't match my standards. Is there any helpful comprehensive course that helps with writing and speaking in American English? Not duolingo/cambly please. Individual instructors sound perfect for me if you have a good experience with one, please share it below. Thank you!
Listen to other ppl and how/what they say. Read industry related topics.
Read more books. You'll subconsciously pick it up.
For written, if the company allows, Grammarly is really good.
If you are Amazon look up Doc Bar raisers and ask to work 1:1 with them to assess your writing. Take a-z writing at Amazon course. Im teaching one in march. Btw I think it may be a type of imposter syndrome if you feel like this. Writing big words does not make you a better writer, FYI. The goal should be making it simple for the target audience to understand your point.
You want to lose your accent or what ?
No, just advance/revise grammar and getting rich voc
Read books