I've done it. Its an odd combination. On one hand they know the ATC
system very well (although I've found they believe the VFR system is
more restrictive than it is), on the other hand, there is some basic
stick-rudder items that they will be lacking.
I did a C-182T (glass cockpit) checkout with a 727 pilot once. When I
asked him to do power on stalls, the thought occured to me to ask him
if he knew which rudder was going to be needed to stay coordinated in
the stall. "Left?" he said.
My pointis that you need to remember that, dispite your student's
knowledge in some areas, he's a student pilot in others.

-Robert, CFII


Emily wrote:
And for some reason he's picked me for the honor of training him.

But I'm a little confused on one thing. He claims to have a
commercial-multi, limited to centerline thrust, and an ATP multi,
unrestricted, with 737 and 757/767 type ratings. I wasn't aware that
you could have both those certificates...is that true?

And if it is, onto which certificate does the single engine airplane add
on go?

And one last question. I know I'd never, ever, train a primary student,
as long as it's been since I instructed, but this shouldn't be a huge
deal, right?