How do Subway employees actually know how their sandwiches?

They train you when you start. Some places have you start on veggies, others have you start on meat and show you how to cut the bread. Later on you'll learn how to do register. There are also papers on your side of the line that show the recipes for each sandwich if you need help. When you start they should also give you a paper to study with the recipes to most of the sandwiches.

I don't think they have the recipes on the website, but you can look on there to see the different types of bread that there are and sauces. Each restaurant may have a few different sandwiches, toppings, and sauces though.

There's a chart on the back of the counter that tells you how to make them

im sure they will train you for a day or two i dont think they will just ask you to start making sandwiches

they will train you for a couple days and show you everything just write everyhting down so you remember and can study it