Опять английский....Хелп ми!

Я не понимаю, как вообще делать всякие эти задания на времена...Ну не могу я! Помогите плиз... Тhe letter contains 12 mistakes in tenses, vocabulary and spelling. Copy the letter and correct the mistakes. Dear Sir or Madam. I am write to ask more informations about the music contest which was advertised in our local newspaper. In fact, my classmates and I were thrilled when we have seen the advertisement but there are some things we can like to find out. To begin, I'd like to know how the exact dates of the contest are, as some of the dates won't be convenient for some of us, due to school timetable. Secondly, as accomodation wasn't mention in your advertisement, I'd appreciate some information concerning hotels in the area where the contest is going to the part. In addition to these, I request information on the number of singers and musicians that are allowed to come. I also doesn't understand whether there is an age limit or not? Finale, we want to know whether the contest are knock-out or they are allowed all the participants to take part in all rounds and how many peoples are expected to participate. I look forward to receiving an answer. That's all for now! William.