Argument 1: - Certain grammatical changes happened in the Indo Aryan (IA) languages at the end of Harappan period.
Hint: - What the arguer hinting here is that when Indo Aryan language Sanskrit ‘came to India’ through North-West, Sanskrit encountered some other, alien language and that alien language influenced Sanskrit and changed the grammatical structure of Sanskrit. Current day Sanskrit and Dravidian languages inhibit certain syntactical similarity. SO the arguer says indirectly that Sanskrit borrowed syntax from Dravidian language. (This is a foolish argument)
Counter argument: -
As per the Language replacement theory, (Sanskrit replaced Dravidian from North-west India), Aryans came to Harappa from outside, as invasion or immigration, and were the cause of the destruction of it. But how linguistics can measure the grammatical changes in Indo Aryan languages, at the very initial period of their 'arrival'? Sanskrit speaking people just 'arrived' in Harappa and began to compose Rig-Veda. Then, how linguistics can measure the grammatical changes in the newly introduced Sanskrit. (Normally we need a back up repository of a language, with which the 'grammatical changes' will compare to make sure that 'grammatical changes’ actually happened. In this scenario where is the backup repository Sanskrit language? Also whichever language influenced Sanskrit to cause ‘grammatical change’, that language is not constructed or not revealed or discovered. Linguistics are just ‘assuming’ that ther was a language at the time of ‘arrival’ of Aryans.
This mythical grammatical change happened to a ‘influenced language’ at the early period, without the supplement of ‘influencing language’ is purely farcical. In fact grammatical changes can’t measure at the very early dates precisely.
Argument 2: - Brahui (& Munda) is evidence which shows that Dravidian Languages were once spread all over the North and North-West India.
Hint: - Brahui is a language spoken in Baluchistan and a part of Afghanistan which share similarity with Dravidian languages. Since there is no Dravidian Language nearby areas a few ‘scholars’ says it was the remnant of the Dravidian language of Harappan Period. But common view is that Brahui language is a recent migration to Baluchistan after 1000 CE. The main argument which lies behind this Brahui, is that there was a Dravidian Language in North-West India at the time of ‘arrival of Aryans’ to India.
Refutation Comment 1: -
‘Experts’ who support Dravidian language theory are speaking about a mythical language and about a mythical population who spoke that language, at the Late harappan Era. The earliest historically attested Dravidian language is in Sangham Literature around 300 BC (or to the max. 500 BC). (Indus script is not deciphered and in every respect it can’t be Dravidian). And the earliest attested Sanskrit, is in Rigveda, which dates to the minimum 3000 BC. (Read: "On the trail of Saraswati" by Michel Danino for Rigveda dating. My review on the same book here => http://goo.gl/UfmWvG )
Without verifying the existence of any language prior to Rigvedic Sanskrit, western 'scholars' are blatantly bringing the mythical language to denounce Rigveda and Indian culture. Can these ‘scholars’ re-construct the Mythical language, be it Munda or Dravidian? Of course not. All of the false claims regarding a Dravidian language at the time of the ‘arrival of Aryans’ and its subsequent destruction/replacement by the Aryans are the result of defective scholarship and reflects the 19th century cultural milieu of Europe. There is no proof for the existence of any language prior to Rigvedic Sanskrit. Without reconstructing at least a part of the mythical/Dravidian language, how 'scholars' can claim that that language influenced Sanskrit? Rigvedic Sanskrit grammar (3000 BC) should be compared with the mythical Dravidian language of that period (3000 BC). Not with the Dravidian language of 300 BC / 2000 AD.
Refutation Comment 2: -
In order to have a valid replacement theory, (Dravidian replaced by Sanskrit), the existence of Brahui/Dravidian language at the time of Late Harappan period should be verified beyond doubt from primary sources. Replacement theorists should prove that ancestor of Brahui existed in Indus valley during the Rigvedic era. Brahui or Dravidian languages should be well attested in archaeological or linguistical evidences from or prior to Rigvedic era. Currently no such sources are available either as linguistically or archaeologically. Replacement theorists can’t argue that now (2014 AD) there is Brahui. So does in BC 2500. If they want to argue, they should provide evidence for the existence of Brahui at that time, using the material from that ancient time. (As with Indus script, It is not accepted among experts as Dravidian. Certain studies shows Indus script as Brahmi/Sanskrit, See: Subhash kak and SR Rao). Additionally Indus valley archaeologists (JM Kenoyer and J Shaffer) are of the opinion that no invasion/immigration happened in Indus valley area between 4500 BC - 400 BC. (Read my review of Kazanas Book => http://goo.gl/UQMAfk ) Dravidian element have no role in this scenario because to say it Dravidian an invasion or immigration is a must. Further more there are linguistic studies which show that Brahui, Munda, et all are recent immigration to their current inhabitant areas. I.e., long after Rigvedic period. Read: Edwin Bryant, ‘the quest for the origin of Vedic Culture’. (Linguistics can determine the Language's antiquity by measuring the changes happened inside the concerned language.)