In the late stone age, about seven or eight millennia ago, the speakers of the cluster of related dialects that later developed into Sanskrit, Greek, Latin and most of the modern European languages, lived in a habitat where man, today the most influential and dominant life-form on the planet, was nothing more than a small and insignificant guest without anything to call his own. It was a world where the traces of the man’s presence were limited to a few holes left by tent pegs and the ruts of chariot-wheels in the virgin soil of a planet that must have felt vast beyond comprehension. It was a world filled with tangible magic, where the raw energy of a horse could inspire awe, which is for us today difficult to understand. What then, of what has, after so many millennia, still the power to make us feel like an insignificant and friendless guest in a vast palace vaulted by the revolving of a thousand worlds? Nothing made a deeper impression on these first Indo-Europeans, than the stage of the rise and set of the luminaries and of a thousand atmospheric battles resounding with the thundering groan of wounded celestial beings. Some of the older Indo-European languages, such as Sanskrit and ancient Greek, contain exactly corresponding traces left by this wonder in the soil of morphology. These traces are the word for sky and its distinctive paradigm using two separate roots for different case forms. In both languages this word was frequently joined to the noun father to make Father Sky: Ζευς πατηρ (Zeus patēr) in Greek and द्यौः पिता (dyauḥ pitā) in Sanskrit. Below, a description of the correspondences between the paradigms of the etymologically identical word sky in Greek and Sanskrit.
1. Nominative: Ζευς (Zeus) in Greek and द्यौः (dyauḥ) in Sanskrit. The nominative of both words is based on a root with a diphthong and the initial consonant cluster dy. It is a law of Greek phonology that this cluster turns into z (pronounced zd in classical pronunciation). In Sanskrit the final s, visible in Greek in its original form, always becomes an aspiration called visarga. Once one is aware of these two rules of sound change the two forms correspond exactly.
2. Accusative: Ζην (Zēn) in Greek and द्याम् (dyām) in Sanskrit The accusative is based on the same root as the nominative. Both forms correspond in having a long vowel. The difference in the nature of the final nasal is due to another law of Greek phonology: final m becomes n. This is a pervading sound change that affects all forms of Greek having a final m. The characteristic sign of the accusative was m and this always appears as n in Greek, e.g. ἵππον (hippon) is the accusative of the word horse, which in Sanskrit is अश्वम् (aśvam).
3. Genitive: Διος (Dios) in Greek and दिवः (divaḥ) in Sanskrit. The remaining cases are constructed on an alternative root div-. What is immediately evident is that the Greek form lacks the sound v. This is due to the fact that this sound was entirely lost in Greek after about 1000 BC. Where there is v in another language, there will always be a blank in Greek. Before this loss the Greek form must have been Divos. That the o of the Greek form is an a in Skr. is to be expected because the short vowels e, o and a all become a in Sanskrit, a phonological development called the Indo-Iranian merger of short mid and low vowels. This merging of three sounds into one in Sanskrit can most clearly be seen when one compares the perfect forms of the verb to see in Greek and Sanskrit: δεδορκα (dedorka), containing all the three short vowels in question, and ददर्श (dadarśa) in Sanskrit, which exhibits a reduction in vowel contrast from three to one. Again the final s of Greek is represented by the aspiration visarga in Sanskrit.
4. Dative/Locative: Διι (Dii) in Greek and दिवि (divi) in Sanskrit. The Greek dative singular originally was a locative and always corresponds to the form of this case in Sanskrit. The Greek form again exhibits loss of the sound v.
Silvio Zinsstag,
teacher for ancient languages