Assure vs Make sure

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

Assure

Top 1,000 (very common)B2verb

Make sure

Top 1,000 (very common)
 AssureMake sure
Pronunciation🇬🇧 /["/əˈʃʊə(r)//əˈʃɔː(r)/","/əˈʃʊəz//əˈʃɔːz/","/əˈʃʊəd//əˈʃɔːd/","/əˈʃʊərɪŋ//əˈʃɔːrɪŋ/"]/🇺🇸 /["/əˈʃʊr/","/əˈʃʊrz/","/əˈʃʊrd/","/əˈʃʊrɪŋ/"]/🇬🇧 //meɪk ʃɔː//🇺🇸 //meɪk ʃʊr//
MeaningTo make someone feel sure about somethingCheck that something is done or true.
ExampleI assure you that everything will be fine.Make sure you lock the door before leaving.
RegisterNeutralNeutral
How commonTop 1,000 (very common)Top 1,000 (very common)
CEFR levelB2-
Part of speechverb
Collocationscan, hasten to, of, let me assure youmake sure that, make sure to, make sure you, make sure everything, make sure it is
Antonymsdoubt, disprove, deny-
Common mistakesConfused with 'ensure' which means to make certain something happens., Using it without a direct object; 'I assure that...' is incorrect., Mixing up 'assure' with 'insure' which relates to insurance.Using 'make sure' without a clause, e.g., 'Make sure.' instead of 'Make sure it's correct.', Confusing 'make sure' with 'ensure'; they are similar but 'ensure' is more formal., Omitting the subject in sentences, e.g., 'Make sure you're prepared.' instead of 'You need to make sure you're prepared.'
Usage notesUse 'assure' when you want to promise someone that something is true or will happen. It’s often used in more formal situations. Avoid using it in casual conversations where simpler verbs like 'tell' or 'say' might fit better.Use 'make sure' in everyday conversation to emphasize confirmation. It's appropriate in both casual and professional settings but avoid overly formal contexts.

Frequently asked questions: Assure vs Make sure

What's the difference between Assure and Make sure?

Assure: To make someone feel sure about something Make sure: Check that something is done or true.

Can you show an example of each?

Assure: I assure you that everything will be fine. Make sure: Make sure you lock the door before leaving.

Can I use Assure and Make sure interchangeably?

Not always. Assure and Make sure 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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