怎么写信,

Informal letters:Sender's address(leave a line)date(leave a line)salutation(Dear Sam)(leave a line)Hi。Write soon,won't you?(leave a line)With loveJohnFormal letters:Sender's addressdaterecipient's nameposition( Principal,Flower Secondary School)recipient's addresssalutationI am。I am writing this letter to。Thank you for your kind attention。Yours sincerely(if you know the person)/ Yours faithfully (if you don't know the person)your name一般来讲正文以外都没有标点符号,也就是说yours sincerely 这样的之后都不加逗号,但是要求也不是总是那么严格。