Marker (linguistics)
In linguistics, a marker is a free or bound morpheme that indicates the grammatical function of the marked word, phrase, or sentence. Most characteristically, markers occur as clitics or inflectional affixes. In analytic languages and agglutinative languages, markers are generally easily distinguished. In fusional languages and polysynthetic languages, this is often not the case. For example, in Latin, a highly fusional language, the word amō ("I love") is marked by suffix -ō for indicative mood, active voice, first person, singular, present tense.