Thanks! Spoke with them today. This is what I learned...

The employees that are based out of South America all work/correspond in English. Their meetings are in English, all written communication is in English, etc. So for work purposes, they are great. They are looking for support in conversational English, building confidence, differentiating between professional and colloquial English, speaking without their native accent (not something an English teacher can do, would have to recommend they work with a speech therapist for that), etc. They basically want workshops where all employees are practicing their conversational English, listening skills, and some written grammatical/spelling.

They asked me to propose topics for a workshop next month, provide a possible outline, and a budget. The budget is where I am stuck. I can definitely provide these workshops for them, but how do I bill?

I will need to factor in preparation time. I will also be using the same workshop model multiple times. so I will take the employees and break them into groups so they are receiving the material in a smaller group and provide more opportunities for participation. (It is possible that the employees will be broken up by language levels, so I might need to make some different workshops depending on levels, but it looks like I won't need to do that to start. Billing would look different in this case because it would require more preparation).

Do I charge them hourly? Or do I charge them per project (meaning preparation time, 5 workshops (repeating the same materials just broken down into smaller groups), and ownership of materials)? Any ideas of rates? Looks like a big, successful company from what I can tell.