In Modern English, EACH OTHER and ONE ANOTHER are morphologically fixed as reciprocal compound pronouns. The reciprocal construction has been developed and used in every period of the English language. The main purpose of this study, nevertheless, was to investigate the ways to express the notion of reciprocity in Middle English and Early Modern English.The morphological analyses of the citations demonstrate that Middle English employed a great variety of head words and phrases than does Modern English in reciprocal structures. EACH, EITHER, EVERY, and ONE most frequently appear as head words of Middle English reciprocal construction, and OTHER usually occurs as a subsequent elements. OTHER, however, may also serve as the head word. Middle English also permits EACH MAN, ILLC MANN, EACH ONE, ILLC ONE, EVERY MAN, EVERY ONE, and THE ONE to function as head phrases. In Early Modem English, Malory employs various structures in his writings, but he prefers EITHER, EITHER OF (US, YOU, THEM) as the head of reciprocal patterns. Shakespeare, nevertheless, more frequently uses ONE as the head word.In Middle English, according to the data, the reciprocal sequence (EACH, EITHER, ONE) / OTHER stands in subject position in twenty examples between c. 1200 - c.1450. Rarely, however, do the pronouns function as a compound subject (subject / complement). The underlying structure of the sentence pattern SOV, nevertheless, is SVO. The need to rhyme, therefore, may cause the change of the word order in the period.(EACH, EITHER, EVERY, ONE, OTHER) may be compounded with the pronoun OTHER in forty examples between c. 1285 - c.1513, but the sequence most frequentlyoccur as direct / indirect object. (EACH, EITHER, EVERY, ONE, OTHER) + OTHER functions as object of preposition in four examples between c.1328 - c.1440.The modem usage of EACH OTHER as a compound object is established in Early Modern English learned, imaginative texts, and the use of ONE ANOTHER as the compound direct object and object of preposition are being established in that period.Since the rules for compounding reciprocal pronouns and for their morpho-syntatic features were not restrictly established before the time of Shakespeare, OTHER could function as an uninflected, separable pronoun in Middle English. In position except modification. the development of OTHER as a nominal occured after Middle English except where the head word is ONE. In Modem English, OTHER must be used as a nominal if the reciprocal pronouns are not compounded. / Department of English