UK:*UK and possibly other pronunciationsUK and possibly other pronunciations/əˈʃʊər/US:USA pronunciation: IPA and respellingUSA pronuncation: IPA/əˈʃʊr/ ,USA pronunciation: respelling(ə shŏŏr, ə shûr)

Inflections of 'assure' (v): (⇒ conjugate)
v 3rd person singular
v pres pverb, present participle: -ing verb used descriptively or to form progressive verb--for example, "a singing bird," "It is singing."
v pastverb, past simple: Past tense--for example, "He saw the man." "She laughed."
v past pverb, past participle: Verb form used descriptively or to form verbs--for example, "the locked door," "The door has been locked."
WordReference Collins English Usage © 2020
assure - ensure - insure
If you assure someone that something is true or will happen, you tell them that it is definitely true or will definitely happen, often in order to make them less worried.
"I can assure you that neither of our two goalkeepers will be leaving," O'Leary said.
The government assured the public that there would be no increase in taxes.
‘ensure’ and ‘insure’
In British English, to ensure that something happens means to make certain that it happens.
His reputation was enough to ensure that he was always welcome.
In American English, this word is usually spelled insure.
I shall try to insure that your stay is a pleasant one.
Insure has another meaning. In both British and American English, if you insure your property, you pay money to a company so that if the property is lost, stolen, or damaged, the company will pay you a sum of money. In this meaning, the spelling is always insure, not ‘ensure’.
Insure your baggage before you leave home.
'assure' also found in these entries:

Report an inappropriate ad.