AbstractI started from the relative clause which occurs in Hittite, and in particular with the enclitic position of the relative pronoun. This is connected with the OV position and this position seems to have been prevailing in Hittite and PIE. The syntactic structure usually employed in Hittite between different clauses is the parataxis. Nevertheless, also the hypotaxis begins to be employed and the best occasion to use it was the diptych as suggested by Haudry, though he didn't consider the most natural and usual diptych: the law, where the crime and the sanction build a natural diptych already in old Hittite. Then I used Justus' and Boley's discussion on the structure of Hittite sentence and found a similarity with Latin, namely the use of an animate subject as central point of a sentence. With verbs of action in ancient languages the subject was normally an animate being, whereas also inanimate subject is employed in modern languages. This seems to be the major difference between ancient and modern structure of a sentence, or, better to say, in Hittite and PIE the subject was an animate being and this persisted a long time, and remained as a tendency in Latin, while in following languages and in classical grammar the subject became a simple nominal “entity” to be predicated and precised with verb and other linguistic instruments. A glance has been cast also to pronouns and particles (sometimes linked together) as instruments of linking nominal variants of coordinate or subordinate clauses and to the development of demonstrative/deictic pronouns. Also in ancient case theory a prevailing position was assured to the nominative case, the case of the subject.