As is often the case with derivational morphology, many English prefixes can only be added to bases of particular lexical categories (or "parts of speech"). For example, the prefix "re-" meaning "again, back" is only added to verb bases as in "rebuild", "reclaim", "reuse", "resell", "re-evaluate", "resettle". It cannot be added to bases of other lexical categories. Thus, examples of "re-" plus a noun base (such as the ungrammatical "*rehusband", "*remonopoly") or "re-" plus an adjective base ("*renatural", "*rewise") are virtually unattested.