stems may be a root, e.g. "run", or they may be morphologically complex, as in compound words (e.g. the compound nouns "meat ball" or "bottle opener") or words with derivational morphemes (e.g. the derived verbs "black-en" or "standard-ize"). hence, the stem of the complex english noun "photographer" is "photo·graph·er", but not "photo". for another example, the root of the english verb form "destabilized" is "stabil-", a form of "stable" that does not occur alone; the stem is "de·stabil·ize", which includes the derivational affixes "de-" and "-ize", but not the inflectional past tense suffix "-(e)d". that is, a stem is that part of a word that inflectional affixes attach to.