Answer:
Dear sister,
I hope you are doing well. Mum told me that you were admitted into my former school congratulations! Let me give you some helpful advice to have the best experience possible and the best grades.
You should always pay attention in class and not speak with your classmates, especially during Math class with Mr. Jenssen. He is a strict teacher who will give you extra homework if you misbehave during his lessons. On the other hand, he is a good teacher who is always willing to help when you struggle with the given tasks.
The school has a strict dressing code. Be sure to wear the appropriate attire. Do not wear short skirts or short t-shirts since teachers will send you to detention, and what is more, you will have to wear gym clothes for the rest of the day.
The school is one of the best in our state. You must study hard to pass all your exams. Also, there are many different clubs that you can join. I know that you like reading, the school has a literature club where they discuss new books every week, you should become a member since I'm sure that you will make a lot of friends with the same interests as you.
I have to go now, but I hope that you find this information helpful. Do not hesitate to contact me if you have any doubts or need advice.
All the best.
Susan.
Explanation:
A letter to a friend or a relative should have informal language. That is to say that we can use informal words and contractions.
When we write a letter, we have to divide it into three main sections. First, we have the introduction where we address the reader, ask how she is doing, and introduce the letter's topic. In the following section, we give suggestions and information. This section can have multiple paragraphs. Lastly, we have the closing paragraph. We have to say our goodbyes and ask the reader to write if there are any doubts.