We had to climb another 'flight/set of stairs' to get to the roof.
He tripped on the bottom 'stair' and almost fell.
He waited at the foot/bottom of the 'stairs'.
(..) I'll whip their butt too. Those stairs won't know which way they're goin'. I'm gonna take drastic steps. Kick it to the kerb. Don't mess with me. I'm the stair master. I've mastered the stairs. I wish I had a step right here. I'd step all over it. Well, at least we know (..)2001 Shrek