morphology, in linguistics, study of the internal construction of words. Languages vary widely in the degree to which words can be analyzed into word elements, or morphemes (q.v.). In English there are numerous examples, such as “replacement,” which is composed of re-, “place,” and -ment, and “walked,” from the elements “walk” and -ed. Many American Indian languages have a highly complex morphology; other languages, such as Vietnamese or Chinese, have very little or none. Morphology includes the grammatical processes of inflection (q.v.) and derivation. Inflection marks categories such as person, tense, and case; e.g., “sings” contains a final -s, marker of the 3rd person singular, and the German Mannes consists of the stem Mann and the genitive singular inflection -es. Derivation is the formation of new words from existing words; e.g., “singer” from “sing” and “acceptable” from “accept.” Derived words can also be inflected: “singers” from “singer.”