potwierdzać

Etymology
From.

Verb

 * 1)  to confirm, to corroborate
 * 2)  to make certain of something, to reassure about something
 * 3)  to agree to something, to concede to someone
 * 4)  to confirm
 * 5)  to be confirmed, to be corroborated
 * 6)  to confirm one's suitability for something, to prove oneself in an activity
 * 1)  to agree to something, to concede to someone
 * 2)  to confirm
 * 3)  to be confirmed, to be corroborated
 * 4)  to confirm one's suitability for something, to prove oneself in an activity
 * 1)  to confirm
 * 2)  to be confirmed, to be corroborated
 * 3)  to confirm one's suitability for something, to prove oneself in an activity
 * 1)  to be confirmed, to be corroborated
 * 2)  to confirm one's suitability for something, to prove oneself in an activity
 * 1)  to be confirmed, to be corroborated
 * 2)  to confirm one's suitability for something, to prove oneself in an activity
 * 1)  to confirm one's suitability for something, to prove oneself in an activity