What are two factors that determine the tone of a business letter?

1. The purpose of the letter. Is the letter intended to inform, persuade, or request something? The tone of the letter should be appropriate for the purpose. For example, a letter that is intended to inform should be clear and concise, while a letter that is intended to persuade should be more persuasive and engaging.

2. The audience for the letter. Who is the letter being written to? The tone of the letter should be appropriate for the audience. For example, a letter that is being written to a customer should be more customer-focused and friendly, while a letter that is being written to a colleague should be more professional and formal.