Formal English and the english used on the internet are often quite different. The best material for study is the forum you intend to post in.
However, 'passing' as being competent is English is not too hard if you strive to keep your thoughts brief and sentences short, just like your OP. Avoiding some elementary mistakes will allow you to blend right in.
- The capitalisation of words is important, it can single you out as being retarded, an old person, a mistake, or an ESL. Remember to keep it consistent; for one, the start of every new sentence has a Capital. There is many more rules and a lot of nuance to this.
- Long unbroken sentences are hard to read, so be sure to use punctuation often, but periods (.) are not commas, so don't stop a sentence. where you should be instead be using a comma.
- Don't randomly break your paragraph and make a new line unless you know why you are
doing it.
- Sometimes it's inevitable that you have to make a big wordy paragraph, and your accent (from any lack of proficiency) may become obvious. This is simply something you have to work out with lots of practice. Posting lots, comparing and reevaluating your past writing is how to improve, very much the same as native speakers. If you do care deeply about any negative 'ESL!!' type feedback while doing so, there are many alternative and better forums to practice your English than with 4chan.
It ultimately depends on what you consider a proficient speaker as to how far you will need to go. Other English learners may have some thoughts that may be more helpful for you. Good luck~
