The three letter types (and how to spot which one you need)

The prompt always tells you who to write to and gives 3 bullet points to cover. Identify the register from the recipient and situation:

TypeWrite toOpen withSign off
FormalA company, manager, authority, unknown personDear Sir or Madam,Yours faithfully,
Semi-formalSomeone you know professionally — a landlord, a colleagueDear Mr./Mrs. [Name],Yours sincerely,
InformalA friend or family memberDear [First name],Best wishes,