Hi, I would change that sentence this way: I was amazed by how fluent your Korean is especially considering the fact you've been self taught. ---> Correction ---> I was amazed by how fluent you are in Korean, especially considering you're self-taught. Americans often use 'fluent' with 'be' verbs in sentences -- "I am fluent', 'she is fluent', etc. You could also say "...how fluently you speak Korean", or "how well you speak Korean". Using 'been' with 'self-taught' seems unnecessary, because been + taught emphasizes the passive quality and past tense state of been --- someone else performed an action on the person, they 'taught' the person, so the person has 'been taught' something, and received the action of teaching. But *teaching yourself* is more active, and I would use "You ARE* self-taught". Most of the time when I hear this, it's used in the present tense, because, in a way, the person's state of being self-taught that we're describing is an ongoing state . -- "She is self-taught. He is a self-taught musician", for example. It CAN be talked about in the past tense, but I think in this case it sounds more natural to use present tense, unless you say something like 'you've been teaching yourself', or 'you've been learning on your own'. I don't think using 'been' with self-taught' is INCORRECT, I just wanted to offer a way that I, an American tutor, would phrase this. I think to keep the sentence the way it is with basic corrections, not adjusting it to be 'conversational' (as I did above), I would change it to: I was amazed by how fluently you speak Korean, especially considering the fact that* you've been self-taught. Corrections: change to 'how fluently you speak' instead of 'how fluent your Korean is' ; add a comma to separate the long phrases, add 'that' after 'the fact' for clarity, and add a dash for self-taught. More than I thought I would write, but hopefully it helps! Feel free to contact me for a lesson anytime. Sincerely, Jade Palmer

Looks fine .I would add a dash between self and taught, so it would be self-taught. Also agree with the previous comment.

To me, your sentence seems perfect. I would only add a comma before "especially" and "that" after "the fact".