assure

Assure is a transitive verb whose core sense is to promise, guarantee, or convince someone that something is true or will happen, thereby dispelling doubt or providing confidence. It can also mean to remove someone’s concerns by offering reassurance or evidence of security. The noun form is assurance.

The word comes from Old French assurer, likely derived from Latin securus meaning safe or secure. In English, assure has retained its emphasis on interpersonal communication—the speaker’s commitment or certainty conveyed to another person.

Usage and grammar are centered on the pattern with a person as the indirect object and a complement describing the claimed certainty. Typical constructions include assure someone of something (I assure you of my dedication), assure someone that-clause (I assure you that the report is accurate), and, less commonly, assure oneself of something (to become confident about something). The subject is the person giving the assurance, and the recipient is the person being reassured.

Assure is often contrasted with ensure and insure. Ensure means to make certain that something will happen and does not inherently involve addressing a person. Insure refers to protection against risk, typically by insurance. Reassure is closely related but focuses more on calming anxiety or doubt after concern has arisen, rather than providing a new or explicit guarantee.

Examples include: She assured him of her support. We assure you that all safety protocols are followed. The manager assured the team that the deadline would be met.