On this page14 sections
- Quick picker
- Synonyms that mean "take action so it happens"
- Synonyms that mean "promise the result"
- Synonyms that mean "get" or "win"
- Synonyms that mean "keep safe"
- Synonyms that mean "check it is true"
- Synonyms that mean "make it certain or unavoidable"
- Synonyms that mean "make it possible"
- Ensure vs insure vs assure
- Common mistakes
- Example sentences
- Practice
- Quick answers
- Related pages
The most common synonyms for ensure are make sure, guarantee, secure, see to it, confirm and safeguard. In everyday English, “make sure” is the closest match and the one people use most: Please make sure the door is locked means the same as Please ensure the door is locked, only less formally.
The others each add something. Guarantee promises the result, secure means getting hold of something (a deal, a seat, funding), safeguard means protecting it, and confirm means checking that it is already true. Choosing well depends on which of these you mean. Below, the synonyms are grouped by meaning, with example sentences, the difference between ensure, insure and assure, the mistakes people make with them, and a short practice set.
Quick picker
| You mean… | Use | Register |
|---|---|---|
| take action so something happens | make sure, see to it that, ensure | everyday to formal |
| promise that something will happen | guarantee, promise, assure (someone) | neutral |
| get or win something | secure, obtain, lock in | neutral to business |
| keep something safe | safeguard, protect, preserve | neutral to formal |
| check that something is already true | confirm, verify, double-check, check | neutral |
| make something certain or unavoidable | cement, clinch, seal, make certain | neutral to informal |
| make something possible | enable, allow, pave the way for | neutral to formal |
Synonyms that mean “take action so it happens”
This is the core sense of ensure: someone does something so that a result follows.
- Make sure – the everyday equivalent. Make sure you save the file before you close it. It works in speech, emails and instructions. In most emails, “please make sure” sounds friendlier than “please ensure”.
- Make certain – a little more formal and emphatic than make sure. The pilot made certain every passenger was seated.
- See to it that – take personal responsibility for a result. I’ll see to it that the invoice goes out today. It sounds firm, sometimes like an order: See to it that this doesn’t happen again.
- See that – shorter and slightly old-fashioned. See that the children are in bed by nine.
- Take care that / take steps to – formal, common in policies. Staff must take steps to prevent unauthorised access.
- Arrange for – organise something so it happens. We’ll arrange for a taxi to meet you at the station.
Synonyms that mean “promise the result”
- Guarantee – stronger than ensure: it promises the result, often formally. The warranty guarantees a free repair for two years. Use ensure when you will do your best and guarantee only when you can stand behind the outcome; “we guarantee delivery by Friday” invites a complaint if it arrives on Saturday.
- Promise – personal and informal. I promise it’ll be ready tomorrow.
- Assure – tell a person that something is true or will happen, to remove their doubt. It needs a person as its object: I assure you the payment is on its way. (More on this below.)
- Warrant – formal or legal: to guarantee in writing, or to justify. The seller warrants that the car has no outstanding finance.
Synonyms that mean “get” or “win”
- Secure – get something after effort, especially something others want. She secured a place on the course. The team secured funding for another year.
- Obtain – formal for “get”. Applicants must obtain a visa before travelling.
- Lock in – informal business English for fixing a good price or rate before it changes. We locked in the fare before prices went up.
- Clinch – finally settle a deal, a win or an argument. The late goal clinched the title.
Synonyms that mean “keep safe”
- Safeguard – protect from harm or loss; common in law, health and data protection. The new rules safeguard patients’ records.
- Protect – the general word. A strong password protects your account.
- Preserve – keep something as it is. The museum preserves the original manuscripts.
- Uphold – keep a standard, a right or a law in force. The court upheld her right to appeal.
Synonyms that mean “check it is true”
These are close to ensure in instructions like “ensure the cable is connected”, where the reader is really being asked to check.
- Confirm – check and state that something is true. Please confirm that you can attend. For more ways to ask this politely, see other ways to say “just to confirm”.
- Verify – check carefully, often with evidence. The bank will verify your identity.
- Double-check – check again. Double-check the date before you send the invitations.
- Check that – plain and clear. In user manuals, “check that the power is off” is often easier to read than “ensure the power is off”.
Synonyms that mean “make it certain or unavoidable”
- Cement – make a relationship or a position stronger and more permanent. The joint project cemented their partnership.
- Seal – settle something for good. A second goal sealed the win. Also in “seal the deal”.
- Clinch (see above) – often the final step that makes success certain.
- Determine – in formal writing, to decide or fix an outcome. The vote will determine the budget. It does not mean “make sure”, but it is sometimes used where “decide” would be clearer.
Synonyms that mean “make it possible”
Writers often use ensure where they mean something weaker: that an action makes a result possible, not certain. In that case these are more honest:
- Enable – The grant enables us to hire two more teachers.
- Allow / let – The ramp allows wheelchair users to enter.
- Help / help ensure – Regular backups help protect your work. If you cannot promise the result, “help” is the right hedge.
- Pave the way for – prepare the conditions for something later. The agreement paved the way for a full peace treaty.
Ensure vs insure vs assure
These three come from the same Old French root (seur, “sure”) and once overlapped heavily. Modern usage has separated them:
| Word | Meaning | Example |
|---|---|---|
| ensure | make sure something happens | Ensure that all windows are closed. |
| insure | buy or provide insurance (protection against financial loss) | We insured the house against flood damage. |
| assure | tell someone something to remove their doubts | She assured me that the train was on time. |
- In British English, insure is used only for insurance. In American English, insure is also accepted as a spelling of ensure (“to insure accuracy”), and Merriam-Webster lists that sense, but many US style guides still recommend ensure for it. If you write for an international audience, keep insure for insurance.
- Assure almost always takes a person: you assure someone. You ensure something. I assure you the report is finished is right; I ensure you the report is finished is not.
- In British financial English, assurance is also the word for life insurance (life assurance), because it covers something certain to happen.
Common mistakes
| Not quite right | Better | Why |
|---|---|---|
| I ensure you it will be fine. | I assure you it will be fine. | You assure a person; you ensure a result. |
| Ensure to lock the door. | Make sure to lock the door. / Ensure that the door is locked. | “Ensure to” is common in some varieties of English but is not standard; ensure takes a that-clause or a noun. |
| We guarantee to try our best. | We will do our best to ensure… | You cannot guarantee an effort; guarantee a result or nothing. |
| Please insure the form is signed. (UK) | Please ensure the form is signed. | British English keeps insure for insurance. |
| This policy ensures privacy. (when it only helps) | This policy helps protect privacy. | Ensure promises the result; do not promise more than you can. |
Example sentences
- Make sure everyone has the new password before Monday.
- I’ll see to it that your order ships today.
- The contract guarantees a minimum of twenty hours a week.
- We secured the venue three months in advance.
- Encryption safeguards customers’ card details.
- Could you confirm that the meeting is still at three?
- Her final essay clinched the scholarship.
Practice
A. Choose the best word.
- The manager ______ me that my job was safe. (ensured / assured)
- Before you leave, ______ the oven is off. (make sure / secure)
- We ______ the car against theft. (insured / ensured)
- The company ______ a contract with the city. (secured / safeguarded)
- The new filter ______ the risk of contamination; it cannot remove it completely. (reduces / guarantees)
B. Rewrite less formally: “Please ensure that you have read the attached document prior to the meeting.”
Answers. A: 1 assured (a person is the object); 2 make sure; 3 insured; 4 secured; 5 reduces (guarantee would promise more than the filter can do). B: for example, Please make sure you’ve read the attached document before the meeting.
Quick answers
What is a simple word for ensure?
“Make sure.” It means the same and sounds more natural in speech and most emails.
What is a formal synonym for ensure?
“Guarantee”, “secure”, “safeguard” or “see to it that”, depending on whether you mean promise, obtain, protect or take responsibility.
Is it “ensure” or “insure”?
Use ensure for “make sure” and insure for insurance. American English also accepts insure for “make sure”, but ensure is the safer choice.
What is the opposite of ensure?
Depending on the sense: “prevent”, “rule out”, “jeopardize” (put at risk) or “leave to chance”.