The Hittite language is the dead language spoken by the Hittites. It was used from approximately 1500 BC to 900 BC. Hittite is one of the earliest known Indo-European languages, although marked differences in its structure and phonology have lead some philologists to argue that it should be classified as a sister language to the Indo-European languages, rather than a daughter language.
The Hittite empire was centered in Anatolia. The Hittites themselves called their language Nesili, the tongue of the city of Nesa. It is one of the Anatolian languages. The closely related Luwian was also in use in the Hittite empire, as a sacred language. Hittite proper is known from cuneiform tablets and inscriptions erected by the Hittite kings. The script known as "Hittite hieroglyphics" has now been shown to have been used for writing Luwian, rather than Hittite proper. Later Anatolian languages such as Lydian and Lycian are attested much later; they were spoken in former Hittite territory. These tongues are likely descended from Hittite or Luwian.
Hittite began to be deciphered around during the early 20th century. In 1902 Jørgen A. Knudtzon pointed out that a number of cuneiform tablets discovered in Hittite territory were written in the standard Akkadian language cuneiform script. The syllabary signs of this script enabled the text to be read, and in 1916 Bedrich Hrozny concluded that the language of the tablets was indeed related to the Indo-European languages. Etymological reconstructions enabled the successful decipherment of the language.
As one of the oldest attested Indo-European languages, Hittite is interesting largely because it lacks many of the complications exhibited by older Indo-European languages such as Lithuanian, Sanskrit, and Greek. There are only two genders in Hittite, a common gender and a neuter gender. Nouns have only five cases, as opposed to the eight of Sanskrit and Lithuanian; moreover, some of the five Hittite cases seem instead to be suffixes added to a general oblique case stem. The Hittite verb also fails to exhibit some of the complexities of the Sanskrit or Greek verb. These grammatical simplifications make Hittite seem like a much younger Indo-European language than it in fact is.
On the other hand, Hittite preserves some archaic features lost in other Indo-European languages. In Hittite, laryngeals still appear. These sounds, whose existence had been hypothesized by Ferdinand de Saussure in 1879, were not preserved as separate sounds in any attested Indo-European language until the discovery of Hittite. In Hittite, at least some of the laryngeals are written, usually as h. Hittite differs in this respect from any other Indo-European language, and the discovery of laryngeals in Hittite was a remarkable confirmation of de Saussure's hypothesis.
The preservation of the laryngeals, and the lack of any evidence that Hittite shared grammatical features possessed by the other early Indo-European languages, has led some philologists to believe that the Anatolian languages split from the rest of Proto-Indo-European much earlier than the other divisions of the protolanguage. Some have proposed an "Indo-Hittite" language family or superfamily, that includes the rest of Indo-European on one side of a dividing line and Anatolian on the other.