In this paper illuminated the theory of linguistics, that is in linguistics, especially in Uzbek, a lot of works on lexical synonymy, but grammatical and stylistic synonymy, except for the read works, was studied in passing. Besides it, research the question of synonymy as a manifestation of semantic-systemic relations was considered in the works of S.D.Katsnelson (1965), O.Akhmanova (1957), E.Mednikova (1974), A.Ufimtseva (1967), V.G.Pak (1977), D.N.Shmeleva (1977), N.Bradle (1998), D.R.Dowty (2004), M.Furberg (2002), R.M.Rempson (2001). In Uzbek linguistics, this problem was studied more thoroughly by R.R.Sayfullaeva and J.Sh.Djumabaeva. Synonymous series also form simple and complex subordinate clauses. More often than not, the following...