Write an informal letter. you may answer an actual letter from a friend, write to a friend, or make up a letter. here is your goal for this lesson: write a socially appropriate informal letter remember the things you have learned about writing informal letters. be sure your letter is lively and interesting. make sure your letter contains a salutation, body, closing, and signature. use the level of formality appropriate to the person you are addressing. your letter should be at least 125 words long. you will be graded on the following criteria: 1. letter contains all appropriate elements and length. 2. letter contains appropriate level of formality.