Arthur pauses when she hails him and sets his sword down so that it supports his weight, the tip sinking a few centimeters into the cold earth. He'd been generally aware of her presence nearby with her own weapon and dummy, just enough to note her apparent inexperience. With the sword, anyway; there's nothing about her that suggests inexperience in a field of battle.

"You're in luck, then. I've worked on my swordplay since I was old enough to walk."

Training for a future king; training to qualify for the knights once he was of age; training for Camelot's many tourneys. It was only expected he not let the people (or his father) down by being sub-par. Alien (literal alien) technology may be far beyond his experience or abilities, but swords, at least, he knows.