Typically, a stem remains unmodified during inflection with few exceptions due to apophony (for example in Polish, miast-o ("city") and w mieść-e ("in the city"); in English, sing, sang, and sung, where it can be modified according to morphological rules or peculiarities, such as sandhi).
For instance, in Athabaskan linguistics, a verb stem is a root that cannot appear on its own and that carries the tone of the word.
[3] For example, the stabil- (a variant of stable unable to stand alone) is the root of the destabilized, while the stem consists of de·stabil·ize, including de- and -ize.
For example, the English verb stem run is indistinguishable from its present tense form (except in the third person singular).
English words derived from Latin or Greek often involve the oblique stem: adipose, altitudinal, android, and mathematics.
In the Latin third declension, for example, the nominative singular suffix -s is combined with a stem-final consonant.