Huh? In the USA all residential is single-phase. Although there's a center tapped transformer involved, which is what gets you both 120 V and 240 V from one phase. This arrangement is called "split-phase": https://en.wikipedia.org/wiki/Split-phase_electric_power#Nor...

Name one "household use" in the USA (which is where the author lives) that doesn't use single-phase power? I'll give you a head start, I once lived in an apartment building that used 120V/208V for electric hot water heaters. But offhand I can't think of anything else.