Autofill In A Subform

I manage a self-made database of property deeds for my business. Since it often happens that there are multiple owners and multiple buyers of these properties, and that many of the owners and buyers are the same people from time to time, I think I can manage this database more efficiently by using subforms that autofill when I start to type a person's name. I hope this is possible.

My main table and form are based on the deed description. Each deed will have unique buyers and sellers and each buyer and seller can be on many deeds. Thus far I have created tables and queries for sellers and buyers. The seller subform is set up and can accept entries in the form view. When I scroll from record to record, the names seem to show up where they belong, so I'm happy with that. The problem is that when a name comes up a second (or more often) time, I end up typing the entire name in again. This sort of defeats the purpose of having related tables. How can I get it to recognize that the name is already there and perform an autofill for me? What am I missing?