Hi Ethan, I am not a teacher but the best way to describe how to use "set" is probably by example. If you want to describe a machine or 'part' of a machine, the best way, is to be clear as to what the machine is (unless obvious from context). For example you can say: A radio set A DVD set A television (TV) set These are machines made up of 'different' types of parts, better described as 'components' (or parts), together they make a whole single item! Together they become a 'radio / dvd / TV set'. Separately they are a 'set of components / parts, for a radio / tv etc). Another way to use 'set' (or part of a set) is where you have a group of items that together become a complete 'collection'. For example you can say 'a set of knives or forks' a set of postage stamps or DVD discs or films / photographs etc, anything that has a strong relationship with each other. Here you wouldn't use 'components' you use 'part(s)' e.g. "this spoon is 'part' of that set". So your understanding of how to use 'set' is good. Perhaps think of cars / vehicles / electrical items as machines where the word 'set' comes after the machine e.g. - 'tv / dvd / radio set' and other collections of items as 'a set of'...... e.g. knives / spoons.... I hope this helps you, Steve