"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.

"BREATHE" and "BREATH"

"Breathe" means to inhale and exhale. "Breath" refers to a single inhalation or exhalation. Ex.: Remember to breathe deeply and relax. She took a deep breath before diving.