Your old English teacher should know by now that just because something may be improper it doesn’t make it incorrect. The way people talk is rarely so well thought out that it lacks all redundancy much less perfect grammar. But- by all means, if they want to yell at the cat monster on the rooftop- have at her. But she would likely point out that rooftop might as well be redundant too as the roof is always on top, and how English has some of the stupidest names for things, like “fireplace”, “Wastebin”, “hardcandy”. “Greenbeans”- likely breaking a bone for every silly name she can think of in English till she get’s tired of the screaming… Well- at one point she’d likely do that. She’s a reformed kitty now. She’d just intimidate ’em into thinking she’d do that.