The tradition of diglossia, the simultaneous existence of vernacular and archaizing written forms of Greek, was renewed in the modern era in the form of a polarization between two competing varieties: Dimotiki, the vernacular form of Modern Greek proper, and Katharevousa, meaning 'purified', an imitation of classical Greek, which was developed in the early 19th century and used for literary, juridic, administrative and scientific purposes in the newly formed modern Greek state. The diglossia problem was brought to an end in 1976 (Law 306/1976), when Dimotikí was declared the official language of Greece and it is still in use for all official purposes and in education, having incorporated features of Katharevousa and giving birth to Standard Greek.
Historical unity and continuing identity between the various stages of the Greek language is often emphasised. Although Greek has undergone morphological and phonological changes comparable to those seen in other languages, there has been no time in its history since classical antiquity where its cultural, literary, and orthographic tradition was interrupted to such an extent that one can easily speak of a new language emerging. Greek speakers today still tend to regard literary works of ancient Greek as part of their own rather than a foreign language.[5] It is also often estimated that the historical changes have been relatively slight compared with some other languages. According to one estimation, "Homeric Greek is probably closer to demotic than twelfth-century Middle English is to modern spoken English."[6] Ancient Greek texts, especially from Biblical Koine onwards, are thus relatively easy to understand for educated modern speakers. The perception of historical unity is also strengthened by the fact that Greek has not split up into a group of separate national daughter languages, as happened with Latin.
Greek words have been widely borrowed into the European languages, including English: mathematics, astronomy, democracy, philosophy, thespian, athletics, theater, rhetoric etc. Moreover, Greek words and word elements continue to be productive as a basis for coinages: anthropology, photography, isomer, biomechanics, cinema, physics etc. and form, with Latin words, the foundation of international scientific and technical vocabulary, e.g. all words ending with "-logy" ("discourse"). An estimated 12% of the English vocabulary has Greek origin, while numerous Greek words have English derivatives.