In letters to members of your family, the salutation should be:

My dear Father / My dear Friend / My Dear Sister etc.

Letters to friends and close relations should be written in an easy, conversational style. A personal letter should have the same tone as a friendly chat. And as a general rule they should be unpremeditated and spontaneous compositions.

The body of the letter
The style in which the body of the letter is written depends upon the kind of letter you are writing. The style or tone of a personal letter will be quite different from that of a business letter. The following hints, nevertheless, apply to letters of all kinds.

Every educated person should know how to write a good letter. All of us have to write letters of some sorts at some point of time.

Business letters should be brief and to the point. As we all know, business people are always busy. They will not have enough time to read long, winding letters. Unlike personal letters, business letters are written in a more formal style. Certain polite expressions such as those given below are commonly used in business letters:

You may have verbally accepted a job offer or an invitation. But writing an acceptance letter is still a smart way of formally accepting an offer and expressing your appreciation.