It's not that writing can't help your speech anymore at this point. In fact, it most definitely can. Well, not writing per se, but rather your ability to "create" sentences. Or perhaps I should say, selecting sentence patterns and words that will make your speech better beforehand, then making a point of deliberately using them until they become second nature. Of course, you won't be creating them on the spot... you'll be repeating them instead. But by getting used to saying certain things, some of the things you say will be as good as if you'd taken the time to write them down. My point is that making a point of using these patterns constantly in your writing (e.g. having a list next to you) would obviously help you get used to making sentences the way you want.
It's like learning how to play guitar solos. At one point, it hit me that the best way to get really good at improvising guitar solos was actually to study a lot of guitar licks (i.e. phrasing, patterns, etc) and even devising your own beforehand. That becomes your foundation for when you want to improvise, because it sounds good and you know it!
There's a huge difference between creating sentences on the spot and taking your time to write things perfectly. The former relies on what's become second nature to you for the most part, the later is simply put perfectionism that you can't afford to have in oral speech - unless you work on specific things you need to improve in advance. Hence, why I say that it's ("writing", or better yet in this case, production) fluency in the sense that you don't have to take your time to recall certains words or think to use certain sentence patterns or grammar points that can be helpful.
For instance, I'm sure if you start writing about a topic you don't feel comfortable with yet (e.g. politics, soccer, sci-fi, whatever really) every day, after a short while you'll be much more capable of talking about that topic compared to how you started, even if you don't have a single conversation with someone about these things.
It's like learning how to play guitar solos. At one point, it hit me that the best way to get really good at improvising guitar solos was actually to study a lot of guitar licks (i.e. phrasing, patterns, etc) and even devising your own beforehand. That becomes your foundation for when you want to improvise, because it sounds good and you know it!
There's a huge difference between creating sentences on the spot and taking your time to write things perfectly. The former relies on what's become second nature to you for the most part, the later is simply put perfectionism that you can't afford to have in oral speech - unless you work on specific things you need to improve in advance. Hence, why I say that it's ("writing", or better yet in this case, production) fluency in the sense that you don't have to take your time to recall certains words or think to use certain sentence patterns or grammar points that can be helpful.
For instance, I'm sure if you start writing about a topic you don't feel comfortable with yet (e.g. politics, soccer, sci-fi, whatever really) every day, after a short while you'll be much more capable of talking about that topic compared to how you started, even if you don't have a single conversation with someone about these things.
Edited: 2016-05-28, 9:45 pm