Concordance usually involves the concordance of the value of a grammatical category between different elements of a sentence (or sometimes between sentences, as in some cases where a pronoun is needed to match its predecessor or speaker). Some categories that often trigger grammatical concordance are listed below. The players, like the coach, are on the ground with the flu. Case agreement is not an essential feature of English (only personnel pronouns and pronouns that have casus marking). The correspondence between these pronouns can sometimes be observed: Фразы «accompanied by; as well as; in collaboration with; in collaboration with; including», следующие за подлезащим, не изменяют число подленщщего. . . .