Harry's good at it. Of course he is; he's a lifelong soldier, and he knows how to focus. This may be different than the fighting he's best at, but he's still good at it.

Enjolras doesn't spend too long on the straightforward drilling of clearly telegraphed, isolated punches. This isn't open sparring at all, and it isn't full speed yet. But still, he'll shift to tossing different attacks, singly or in combination, at half-speed, and see what Harry does with them.

If the answer is 'fumbles' or 'does the exact same thing a few times in a row,' he'll pause to show a better variation.

(Unlike Bahorel, Enjolras is not someone who thinks to make conversation while he fights, except as it pertains to immediate practical matters.)