1. In winter, I wear thick slippers at home to keep my feet warm.2. I usually put on a pair of flip-flops when I go out to get groceries.3. Software engineers usually wear sandals to work to keep them comfortable.
 slippers flip-flops sandalslippers = 室內拖鞋flip-flops = 室外夾腳拖鞋，大腳趾跟二腳趾夾住拖鞋帶sandal = 室外涼鞋，通常比拖鞋更結實，更耐穿
I tried to explain how the software works to my dad, but he is slow o the uptake.