厕所 = toilet 卫生间 (literally hygenic room) ,洗手间 (washroom). In English, we also have "powder room," (used by women as a euphemism to reapply their makeup) Like in English, it all depends on who you are with. With family and close friends, you
don't have to overtly polite. 电梯 = elevator, escalator = 电扶梯, 自动扶梯, 电/自动/平梯 etc.