(i) Language is a highly complex phenomenon and the changes that take place in it are too complex to be explained in terms of neatly drawn straight lines. The word “genealogy”, as used in this context, is only a metaphor and like all other metaphors it may completely lose its significance if we stretch its metaphorical meaning beyond a certain point.
(ii) Changes in a living language are slow and continuous and it is very difficult to be exact about the point of time when during its process of change a language ceases to be itself and can be labeled as another language derived from it.
(iii) Tracing the origin of a language and trying to reach the parent language through the various nodes and sub-nodes in a family tree is a hazardous academic exercise. Researchers take great care in reconstructing the languages which are no more and identifying all those languages which “died without issue”. Philologists have done an excellent job in discovering the branches and sub-branches of the Indo-European family of languages.
As Strang (1970:404) has rightly pointed out, “the reconstruction of I.E. (Indo-European) is one of the great achievements of the human intellect in the last century and a half”. In spite of the brilliant work done by philologists there will always be a certain amount of information fog in this context.
No one can, for example, say with certainty how many Manxes, Cornishes, Umbrians and Oscans emerged in history as languages in their own right and then sank deep down into the vast sea of oblivion, not leaving behind even a trace of their existence.
Ancient history has always been full of insurmountable challenges and the history of language poses no less a challenge than the history of any other aspect of human society.
(iv) A genealogical table showing the origin of a language tends to create the misleading notion that the only process of change relevant to a proper understanding of its branches and sub-branches is the process of divergence.
The process of divergence is important no doubt but the process of convergence is no less important. There are examples that show that at times the process of change is reversed and the whole language family or all the languages of a branch are reduced to one language of the family.
The genealogical table will show that Latin was only one of the many descendants of the Italic branch. For political reasons it became more dominant than its sister languages like Oscan and Umbrian and then ultimately absorbed and fully assimilated those two sister languages of the Italic branch.
It needs to be pointed out here that a number of phonetic changes took place during the process of the Indo-European family dividing itself into a number of branches. Nineteenth-century philologists who studied many of these phonetic changes realized that some of these changes were in the form of regular patterns and on the basis of inductive evidence they could be established in the form of scientific laws. Two such laws established by nineteenth century philologists will now be discussed here in some detail.