in languages with very little inflection, such as english and chinese, the stem is usually not distinct from the "normal" form of the word (the lemma, citation or dictionary form). however, in other languages, stems may rarely or never occur on their own. for example, the english verb stem "run" is indistinguishable from its present tense form (except in the third person singular). however, the equivalent spanish verb stem "corr-" never appears as such because it is cited with the infinitive inflection ("correr") and always appears in actual speech as a non-finite (infinitive or participle) or conjugated form. such morphemes that cannot occur on their own in this way are usually referred to as "bound morphemes".