"ENSURE" and "INSURE"

"Ensure" means to guarantee or make certain. "Insure" refers to obtaining insurance coverage. Ex.: Please ensure the door is locked. We need to insure our new car.

"STATIONARY" and "STATIONERY"

"Stationary" means not moving or not changing. "Stationery" refers to writing materials, such as paper, pens, and envelopes. Ex.: The car remained stationary at the traffic light. I need to buy some stationery for the office.