Finding the bathroom

¿Dónde está el baño?

DON-deh es-TAH el BAH-nyoh — Where's the bathroom?

"Perdona, ¿dónde está el baño?"
Excuse me, where's the bathroom?

"El aseo" and "los servicios" are common alternatives you'll see on signs in Spain, but "el baño" is understood everywhere and is the safest default to ask with.

"The single most useful sentence I've ever taught anyone. No contest."— Graciela