1. I'd like to think my English itself is pretty good. I always did well in my English / Language Arts classes, and I'm pretty good at noticing typos in other works. While I don't doubt that a few errors of my own slip through, it shouldn't be enough to detract from the story.
2. My brain is the ultimate idea generator, and I have tons of story ideas on my fictionpress and fanfiction.net account (both under the same name as here) to prove it. So lack of story ideas or characters usually isn't an issue for me.
3. As far as fanfics go, I like to think I'm pretty good at "getting into the head" of certain characters. As such my most successful fics tend to be oneshots of a character thinking to themselves, as opposed to a multi chapter fic where there are multiple characters actually doing something.
1. I cannot describe surroundings or "set the scene" for the life of me, mostly because I rarely pay attention to my own surroundings in real life (which has lead to some problems). As a result my stories tend to be overly dialogue heavy, and turn into a boring repeat of "he said, she said, etc." with little to break it up. I can't really even break it up with action scenes either as I also struggle with those.
2. I never have any of my ideas planned out from start to finish. There are always a few scenes in the middle I know I want, and if I'm lucky I'll have the start or end planned out as well, but never both. But as far as a complete outline of start - everything in the middle - ending, it's pretty much never happened. I've only ever finished one multi chapter story because of this, and it was a fanfiction taking the characters of one anime and throwing them into the plot of another, which kind of avoided the problem as the plot was already planned out for me. (Technically I guess I also finished book 1 of an original work based on a RP, but the RP ended up dying so I never got around to finishing the series.)
3. The story I see in my head plays out like a movie, so trying to find the words to translate that into book form isn't always easy. I may know what I want a make-believe species to look like, but when I try to type that out it doesn't always end up coming out like I want it to. Part of it is that there's just a limit to written language (a picture's worth a 1,000 words, reading a song will never be the same as listening to it, etc.) and part of it is just my lack of skill as a writer. It also means I hardly ever get anywhere do to trying to revise something a billion times and still not being happy with it.
I guess the tldr version is that I have tons of ideas that will never see the light of day because I'm bad at describing things and never have the full story planned out.