Swing versus Turn

In the early nineteenth century, Thomas Wilson described the difference between swinging and turning this way: "The only difference between swinging and turning is that swinging is always performed with one, and turning with both hands."

There. That's an easy rule to learn and remember.

Turning

If you look at Wilson's diagram below, you will see that his standard turn is clockwise. By the mid-nineteenth century, this is more likely to be called a two-hand turn and it is still done clockwise.

Thomas Wilson, The Complete System of English Country Dancing, London, 1815, p. 9

Swinging

Wilson explains that a swing is done by the lady and gentleman joining hands (notice, this is different from a turn where they "join both hands") and moving in a clockwise path. This means that the lady and gentleman take right hands in a regular swing A swing by the left hand would go counter-clockwise. Wilson's note makes it clear that if you need to use two swings in a row ("turning" and "returning")  the first swing will be by the right hand and the second will be by the left hand..

Thomas Wilson, The Complete System of English Country Dancing, London, 1815, p. 10

I like that Wilson has another way to think of directions. Instead of  "clockwise", he says "the course of the sun" and instead of "by the right hand", he says"to the left".

One big jump you have to make to get into an early nineteenth century mindset is to get comfortable with the idea of "to the left" and "to the right".