Word Stem - Citation Forms and Bound Morphemes

Citation Forms and Bound Morphemes

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); but the equivalent Spanish verb stem corr- never appears as such, since it is cited with the infinitive inflection (correr) and always appears in actual speech as a non-finite (infinitive or participle) or conjugated form. Morphemes like Spanish corr- which can't occur on their own in this way, are usually referred to as bound morphemes.

In computational linguistics, a stem is the part of the word that never changes even when morphologically inflected, whilst a lemma is the base form of the word. For example, given the word "produced", its lemma (linguistics) is "produce", however the stem is "produc": this is because there are words such as production.