I'd like to create a document or template where the majority of the text is fixed, but certain sentences can be swapped in and out based on specific conditions.

For example: If my template is a 3 paragraph letter, if the recipient is a student, I might want change the letter so that the first sentence references his or her studies. If the recipient is not a student, I'd want first sentence to reference their job. Ideally, the person using the template could choose between a number of appropriate options for these customizable parts of the letter.

An advanced version of this might be a form that the user completes (e.g. "Is student? Yes/No) that then auto-populates the letter with the relevant bits of text. But I'd settle for a more simple solution, too!

Thanks in advance for any advice on how to do this!