The four types of letters are as follows:
Personal Letters: These letters are meant for conveying personal thoughts, feelings, or updates to family, friends, or acquaintances in an informal tone and structure.
Business Letters: These formal letters serve business purposes such as job applications, cover letters, or professional correspondence. They usually follow a specific format and are addressed to a specific individual or company.
Social Letters: These letters are used to invite or respond to social events like weddings, birthdays, or other celebrations. They are generally informal in tone and structure.
Official Letters: These are formal letters written by government officials, institutions, or organizations and are used for legal or administrative purposes such as to request information, make a complaint, or to provide official notice. They are written in a formal tone and structure.