1.- After saying "Dear Mr & Mrs Ranken" we must write a colon (i.e. Dear Mr & Mrs Ranken :)

2.- In a first paragraph we make a reference to the letter we are replying (i.e. With reference to your advertisement in …)

3.- The purpose of our own letter, the reason why we are writing, ( i.e. I should like to offer my second home to swap with your semi-detached house in East London during July. ) should always be written in the second paragraph.

4.- In one paragraph we may include the following information:
   a) Say who you are.
   b) Some background information about you.
   c) Explain the reasons why you want something. Give one reason. Then another. Then another one.

5.- Choose the last paragraph to explain any further information you may like to convey. In this very last paragraph, use a standard formula to say goodbye.

6.- Even if a letter of reply is very short, you must always write two or three paragraphs.