Ensure is to MAKE sure of something yourself. "I will ensure the report reaches the boss tomorrow." Assure is to make someone feel sure with words. "I assure you, it will be alright." Insure is to protect with money, usually used when talking about insurance plans. "This plan insures you for doctor visits and hospitalization." Secure is a feeling of safety. "Your home will be secure if you install an alarm."

Hi, just go to www.thefreedictionary.com for word meanings and explanatory sentences.

englishinfocus1.googlepages.com/Assure_Ensure_Insure.htm copy and paste that into your address bar and press open/save when prompted. it's a useful guide to the differences between ensure, assure secure is quite different to the other three. secure: 1) to make secure: to protect, free from attack/danger. eg. the money was made secure. 2) stable/firm, not likely to fail. eg. the house was very secure. hope this has helped (: