"Ensure" = to make certain that something happens; "insure" = to take out insurance or protect financially against loss.
Verb: to take steps to make something certain or to prevent a problem. "Ensure safety" = to guarantee safety. "Please ensure the door is locked" = make certain the door is locked. The subject takes an ACTIVE step to GUARANTEE an outcome. Has no financial or contractual connotation.
Please double-check the figures to ensure there are no errors before submitting the report.
The new procedure was designed to ensure consistent quality across all production batches.
To ensure your reservation is confirmed, we recommend calling the restaurant 24 hours in advance.
Verb: to take out insurance on something or to cover something with an insurance policy to protect against financial loss. "Insure your car" = take out insurance on your car. "The building is insured for $2 million" = the building has insurance coverage of $2 million. Always implies a financial contract and a premium.
It is legally required to insure your vehicle before driving it on public roads in most countries.
They insured the priceless collection for its full replacement value before shipping it overseas.
The musician insured her hands for ten million dollars as a precaution against career-ending injuries.
Common mistake
In colloquial American English, "insure" is sometimes used with the meaning of "ensure" (to make certain something happens). In British English this is less accepted. Safest rule in formal writing: ENSURE to "make certain something happens". INSURE to "take out an insurance policy". There is a related third term: "assure" = to give confidence or reassurance to a person ("I assure you this is safe"). All three are distinct: assure (to people), ensure (outcomes), insure (policies).
Trick to remember it
INSURE has the IN of INsurance. Think: money, premiums, policies, contracts = INSURE. ENSURE = make SURE a result happens = no money involved. Memory trick: INSURE = financial product. ENSURE = guarantee an outcome. Test: can you add "insurance policy" to the sentence? Use INSURE. Does the sentence mean "make certain something happens"? Use ENSURE. "She insured the painting" (insurance policy). "She ensured the painting was safely packed" (made certain it was packed).
Quick rule
Ensure = to make certain that something happens (no money or contracts involved). Insure = to take out an insurance policy (always involves money and a financial contract).
Did you know?
"Ensure" shares its root with "secure" and "sure", from Latin "securus" (free from concern). "Insure" shares its root with "insurance", which came from Italian "assicurare" (to make secure, to guarantee). Interestingly, the third member of the trio — "assure" — comes directly from the same Italian root. All three words share a common Latin prehistory but specialized in English to mean distinct things: guarantee an outcome (ensure), guarantee financial coverage (insure), guarantee by making a promise to a person (assure).
Exercise 1 · Pick the right one
Before launching the product, the team ran extensive tests to _____ that the software worked correctly in all supported environments.
Exercise 2 · Pick the right one
You should _____ the equipment for its full replacement value before shipping it to an international exhibition.
Exercise 3 · Form the word
Ensure = to make certain that something happens (no money or contracts involved). Insure = to take out an insurance policy (always involves money and a financial contract).
In colloquial American English, "insure" is sometimes used with the meaning of "ensure" (to make certain something happens). In British English this is less accepted. Safest rule in formal writing: ENSURE to "make certain something happens". INSURE to "take out an insurance policy". There is a related third term: "assure" = to give confidence or reassurance to a person ("I assure you this is safe"). All three are distinct: assure (to people), ensure (outcomes), insure (policies).
INSURE has the IN of INsurance. Think: money, premiums, policies, contracts = INSURE. ENSURE = make SURE a result happens = no money involved. Memory trick: INSURE = financial product. ENSURE = guarantee an outcome. Test: can you add "insurance policy" to the sentence? Use INSURE. Does the sentence mean "make certain something happens"? Use ENSURE. "She insured the painting" (insurance policy). "She ensured the painting was safely packed" (made certain it was packed).
Bryan López
Founder of SpeakUP Academy