Letters can be written for a number of different reasons and audiences. The content and the language contained within the letter will be affected depending on who the audience is and the purpose of the letter. The level of formality of the letter is dependent on these things. Broadly, letters can be split into two different categories: formal and informal letters.
Normally, formal letters are addressed to people or organisations who the writer does not know directly, or does not know very well. A formal letter can be easy to recognise as the letter will normally be addressed to ‘Dear Sir/Madam,’ or ‘Dear Mr/Mrs [insert surname]’. Standard English will also be used throughout in a formal letter. Examples of a formal letter could include a person complaining to a company about a service they have received or it may be to thank a future employer for a recent job offer.
On the other hand, an informal letter would only ever be addressed to someone the writer knows well; for example, a friend or family member. Because it is informal, Standard English may not be used throughout and there may be the presence of contractions, spoken language features and may even be evidence of a dialect in the person’s writing; for example, ‘wee’ is commonly used in the Scottish dialect to indicate something which is ‘little’.
However, an open letter is a different form of letter altogether. It can be either formal or informal and be addressed to the public or a specific person. The main difference is that open letters are published publicly; this can be in a newspaper, online or read out on the radio etc. Due to them being published publicly, open letters are normally humorous, especially if they are an open letter of complaint.
