Ensure vs Guarantee

When to use each in English, with meaning, register, and examples.

Ensure

Top 2,000 (common)B2verb

Guarantee

Top 2,000 (common)B2verb
 EnsureGuarantee
Pronunciation🇬🇧 /["/ɪnˈʃʊə(r)//ɪnˈʃɔː(r)/","/ɪnˈʃʊəz//ɪnˈʃɔːz/","/ɪnˈʃʊəd//ɪnˈʃɔːd/","/ɪnˈʃʊərɪŋ//ɪnˈʃɔːrɪŋ/"]/🇺🇸 /["/ɪnˈʃʊr/","/ɪnˈʃʊrz/","/ɪnˈʃʊrd/","/ɪnˈʃʊrɪŋ/"]/🇬🇧 /["/ˌɡærənˈtiː/","/ˌɡærənˈtiːz/","/ˌɡærənˈtiːd/","/ˌɡærənˈtiːɪŋ/"]/🇺🇸 /["/ˌɡærənˈtiː/","/ˌɡærənˈtiːz/","/ˌɡærənˈtiːd/","/ˌɡærənˈtiːɪŋ/"]/
MeaningTo make sure something happens or is true.A promise that something will happen or be done.
ExamplePlease ensure that all doors are locked before leaving the building.I can guarantee that you will enjoy this movie.
RegisterNeutralNeutral
How commonTop 2,000 (common)Top 2,000 (common)
CEFR levelB2B2
Part of speechverbverb
Collocationspractically, virtually, effectively, must, aim to, try to, an attempt to ensure something, efforts to ensure something, measures to ensure somethingabsolutely, personally, constitutionally, be able to, can, be fully guaranteed, absolutely, almost, practically
Antonymsneglect, ignoredoubt, uncertainty, dispute
Common mistakesConfused with 'insure' which relates to insurance., Used incorrectly as a standalone verb without an object., Mispronounced as 'en-sure' instead of 'en-shur'.Confused with 'ensure' — 'guarantee' implies a stronger promise., Incorrectly using 'guarantee' without a direct object — always specify what is guaranteed., Mixing up 'guaranteed' as an adjective instead of a past participle.
Usage notesUse 'ensure' when you want to guarantee an outcome or confirm safety. It's appropriate in both spoken and written contexts, though more commonly in formal writing. Avoid using 'ensure' in casual conversations where simpler words like 'make sure' might be more fitting.Use 'guarantee' when you want to express certainty about an outcome. It's suitable for both written and spoken English, but avoid in casual conversations where simpler words like 'promise' may suffice.

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Guarantee

Frequently asked questions: Ensure vs Guarantee

What's the difference between Ensure and Guarantee?

Ensure: To make sure something happens or is true. Guarantee: A promise that something will happen or be done.

Are Ensure and Guarantee the same CEFR level?

Ensure: B2, Guarantee: B2 on the CEFR scale.

What part of speech are Ensure and Guarantee?

Ensure: verb, Guarantee: verb.

Can you show an example of each?

Ensure: Please ensure that all doors are locked before leaving the building. Guarantee: I can guarantee that you will enjoy this movie.

Can I use Ensure and Guarantee interchangeably?

Not always. Ensure and Guarantee are related and overlap in some contexts, but they differ in register, how common they are, and usage, so swapping one for another can change the meaning or tone. Check the differences above before substituting.

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