Formal and Informal Letters

Today for reading we are learning about formal and informal letters. The first one is formal because it uses, 'I am writing to complain' it is very formal to use it and it also uses 'a great deal of litter' instead of 'loads of rubbish'. The second one is informal because it is talking to a friend and it use words like, 'dead busy' and to 'get ready', 'dead busy' is informal language that what it makes the second one informal letter. You can identify if its informal or formal by looking to the language it uses in the letter or text message. You can use informal language if your talking to your friends or family also you can use formal language if you are talking to your teacher, boss and workmates.