1.1 Discovery of the language family

Sir William Jones, colonial judge in India:

 

“The Sanscrit language, whatever be its antiquity, is of a wonderful structure; more perfect than the Greek, more copious than the Latin, and more exquisitely refined than either, yet bearing to both a stronger affinity, both in the roots of verbs and the forms of grammar, than could possibly have been produced by accident; so strong indeed, that no philologer could examine all three without believing them to have sprung from some common source.” (Jones, 1786).

	Sanskrit	Greek	Latin
Verb Roots:	bhar-	pher-	fer-	“carry”  (cf. meta-phor, aqui-fer)
Verb Inflections:	dada-mi	dido-mi	(de-m)	“I give”   (1st person singular)
	as-mi	ei-mi	su-m	“I am”
	as-ti	es-ti	es-t	“s/he is”
Noun Inflections:	vrk-as	luk-os	lup-us	“wolf”   (nominative: subject case)

  1.2 Sub-grouping of Indo-European:                         
                                                                      

Sub-family:	Anatolian	Indo-Iranian	Indo-Aryan	Italic/Romance	Germanic	Celtic
Oldest recorded language:	Hittite	Avestan	Sanskrit	Latin	Gothic	Old Irish

                

	“Centum” (western)			"Satem” (eastern) languages
	Latin	Old Irish	German	Sanskrit	Avestan	Russian	Proto-Indo-European
“hundred”	centum	cet	hundert	satam	satem	sto	khent-
“dog”	canis		hund	svan			*khun- or *khuwon

Tocharian A (Chinese Turkestan):  ku / kon “dog”
-> implication: the sound change [k- > s-] is an innovation shared by the "satem" sub-group

1.3 Reconstruction of Proto-Indo-European:

	Sanscrit	Latin	English	Proto-Indo-European
“horse”	asvas	equus		*akvas or *ekwos
“sheep”		ovis	ewe	*owis