Te article deals with the sentences that contain pragmatic marker I pray you / thee and its variants as a parenthetical clause. Te linguistic material for synchronic analysis is taken from the texts of the plays written by the English authors during the 16−17th centuries. Te examination of the lexicalgrammatical and stylistic characteristics of the structures under analysis shows that the greatest variety of the marker forms is achieved at the beginning of the period under consideration. Te following processes are seen to be the sources of the diversity: the increase of expression by means of an adverb (now, still, hartyly) or a modal verb, the change of the pronunciation of the constituent words followed by modifcations of their representation in the text (comes into I prythee with variants prithee, pr’ythee), the elimination of subject and / or object (resulting in the forms pray, pray you, I pray). Towards the end of the period under consideration, in the second half of the 17th century, the diversity of the variants of the marker decreases, predominantly the following structures continue to exist: I pray, pray and I prythee. Te parenthetical clause is studied in diachrony as well. Te forms of the marker constituents, the peculiarities of the marker word order, the position of the clause in the sentences, the combination with other pragmatic markers are compared with the sentences from the texts of the 14−15th centuries.