Everybody makes mistakes. I don't get annoyed by typos. Misspellings can be a source of amusement -- I spell words wrong quite often, although I make an effort to correct my posts. What irritates me most is incoherent sentences, or semi-sentences (many posters can't compose an actual sentence). I don't like having to guess at the meaning of a headline, or a post. We shouldn't need to guess. When English is used correctly, the meaning is so clear, it is impossible to misinterpret. Word order is very important in English, and I've noticed that most people are not conscious of the importance of word order. You need to re-read your posts, and then ask yourself, "Is there any possible way this can be misinterpreted?" If there is, you need to reorder the words in your sentences.