https://www.punctuationmatters.com/en-dash-em-dash-hyphen/
I didn't even know there was an "en dash" or "em dash". I just assumed varying hyphen lengths were down to font choices. So this is an education. From the examples in the article it looks like I've probably been using commas where an em dash would go.
Now I just have to figure out how to generate them on my keyboard.
Looks like I have to memorise the unicode number to do this. Ugh ..
Hyphen: -
En dash: – (unicode 2013)
Em dash: — (unicode 2014)
@mackaj Led me just now to look up how to do it in MS word. I've had the setting turned on to auto-generate em dashes, but didn't know the other options.