Formal business letter:
A formal business letter is written to notify or inform a person you don’t know (or don’t know well) about something. For example it could be a letter of apology to a library about the books you forgot to return in time or a letter to a landlord describing the accident you had in the kitchen of your rental apartment.
A letter of this type should have 4 paragraphs.
Start your 1st paragraph with “Dear Sir/Madam,” or write the person’s name if it was given in the task statement. Give a short explanation of who you are and why you’re writing.
Your 2nd paragraph should explain in more detail the purpose of your letter. Make sure you write about all the points from the task statement. This should be the longest paragraph of the letter.
In the 3rd paragraph you should say what kind of response you expect or give some suggestions for the situation. If an apology is needed, then this paragraph is the right place for it.
The 4th paragraph should close your letter with a formal ending such as “I am looking forward to hearing from you”, then “Yours sincerely”/”Yours faithfully” and your name.
A personal letter is usually written to a friend or a relative, someone you know well. This is why you should use an informal vocabulary that hints at the close relationship you have with the recipient.
A personal letter can have 3 to 4 paragraphs.
Start your 1st paragraph with a greeting such as “Dear Anne,” or “Hi Robert,” and then write about the purpose of your letter.
Your 2nd paragraph should be all about the purpose stated in your 1st paragraph. Give details, explain, ask, suggest, use your imagination and make this the longest paragraph of the entire letter.
Sign informally, for example “Love, (your name)” or “See you soon, (your name)” would be good endings for a personal letter.