When you try to be perfect, you waste a lot of time working on some minor details almost nobody notices.
What is really important when you write an article is to create a vivid image in your reader’s mind about what you are trying to say. Let’s say a man, in an Armani suit comes to tell you that he wrecked your car by accident. Later, a man dressed like a beggar tells you that he heard on the news that you won the lottery. Which of those two will give you more pleasure? The news is more important than the courier. The message of the article is more important than the way is written and the Grammar.
Of course, you should always try to comb your articles in order to make them look nice. FireFox has a spell checker integrated. When you post your article, FireFox will spot some of your obvious Grammar mistakes. Correct those, then let the article sit on your site!