Prefixed verbs are verbs whose stem begins with an unstressed prefix. The prefix is usually one of "be-", "ge-", "her-", "ont-", "ver-", but others are also possible, often derived from adverbs or prepositions. Prefixed verbs are conjugated like basic verbs, except in the past participle. In the past participle, the inflectional prefix "ge-" is replaced by the verb's own prefix, and it is not added on. The past participle of "heropenen" ("to reopen") is "heropend" (not *"geheropend"), and for "betalen" ("to pay") it is "betaald" (not *"gebetaald").