English belongs, in all its stages, to the Indo-European family of languages, Sanskrit called Indo-Germanic, and still earlier Aryan. 'Indo-European' is the name given to the set of linguistic forms from which nearly all European languages as well as those of Persia and a very large part of India can be shown to have descended.
We do not know that all these prehistoric forms co-existed or that they can properly be said to have been collectively an actual language: for languages and parts of languages change at differing speeds. Nor would it be right to assume that there was necessarily ever a race of people who spoke this Indo-European as their language. Race, culture and language need not always correspond or be coextensive, as may be seen in modern Switzerland. Indo-European is used because it merely suggests that the languages it comprises cover most of Europe and India, or that Europe and India mark the length of its confines.
'Aryan' was the name from the Sanskrit ARYAS 'noble' which the fairer-skinned bringers of the Hindu civilization to India gave themselves to distinguish them from the darker and less cultured peoples whom they largely conquered: and the belief among the predecessors of the more scientific German philologists that Sanskrit, with its remarkably full inflections, was the ancestor of all the then studied European and Asiatic languages, may explain the use of the term 'Aryan' for what we now call Indo-European.
Beginning at some period several thousand years B.C., this 'Indo-European', starting perhaps at a point in Southern Europe near the Asian border, spread itself both East and West. As it spread, with the changing needs of its speakers for different homes, it mixed with many 'non-Indo-European' tongues and was modified by them variously at different stages.
As speakers spread farther and farther from the starting point, their kinds of Indo-European developed more and more qualities, which made them different from their ancestor. In some such way, very broadly, may be described the gradual growth through successive stages of what have become the modern 1-s of Europe, Persia and India as we know them.
There are 8 main groups of Indo-European languages, all traceable back to the Indo-European primitive ancestor. These are divided into roughly an Eastern and a Western set of groups. The Eastern set comprises four groups of languages, which have in common certain basic changes from the original system, such as a general shift in the pronunciation of the so-called 'guttural' consonants [g] and [k] to a 'palatal' position. Thus, for instance, the Indo-European assumed primitive form for the numeral 100 is KMTOM: but whereas languages of the Western set of groups such as Latin (centum) retain the original k-sound, Sanskrit has changed the k- to a sh-sound (satam) and Russian has the word as [sto]
For this reason, the Western languages are commonly referred to as 'Centum' -languages' and the Eastern- after the old Persian or Iranian form of the word-as 'Satem'-languages. The 4 Eastern groups are:
1. Вalto-Slavic- including all the Slavonic tongues ancient and modern and the related 1-s of Baltic countries such as Lithuania and Latvia;
2. Indo-Iranian- including the languages of old and new India of which Sanskrit is the type and of Iran-Persia;
3. then Armenian ancient and modern with its various dialects;
4. and finally Albanian which is only spoken over a relatively small area but forms a separate group by its nature none the less.
The Western groups are:
1. Greek, ancient and modern with their many dialects;
2. Latin and all its derivatives;
3. Celtic which survives in ancient inscriptions and in the medieval and modern languages of Wales, Ireland, the Scottish Highlands and Brittany, and Sanskrit existed in
4. Cornwall and the Isle of Man;
5. and finally the Germanic group, which comprises the languages of Germany,
Scandinavia, Holland and the Flemish parts of Belgium as well as English, and includes these in some ancient and medieval forms also.