Tonia, do you want a website that teaches you about the parts of English that you have listed, or that allows you to practice writing? For a comprehensive and easy to understand website with information on different tenses, prepositions, phrasal verbs, etc. try www.englishpage.com In turns of practicing your writing - I honestly do not know any that are better than here on italki, where you can practice in you notebook and get almost immediate feedback from a huge community of teachers and native speakers. Keep going and you will improve every time. Try and re-write the paragraph once it has been corrected so that you get in the habit of correcting your mistakes. Good luck :)