How do I do fast attacks reliably?

Question

If I attack someone, it won't do fast attacks most of the time. I don't know what triggers it, but it seemingly at random changes between clicks fast attacks and holding the mouse being a defensive stance, and clicks being slower attacks that aren't useful. When the clicks do that, holding the mouse results in a flourishing swing that does absolutely nothing.

What causes the switch between these two modes? I'm still moving as if I'm locked on, and when I'm not locked on I attack and move in a different way.

This is on PC, if you didn't figure that out from the "holding the mouse" thing.

Answer 1

I figured this out, I'm not holding right mouse button. It said to block with button one, I pressed the left mouse button, it blocked (or seemed to.) This is because the tutorial forces you to take the defensive stance and will not let you attack until it asks, meaning I pressed attack and not "defensive stance". You do fast attacks in the defensive stance, and longer attacks outside of it.

I'm still not sure why you do anything but fast attacks though.