Kongu Tamil is the dialect of Tamil language

Tamil language

Tamil is a Dravidian language spoken predominantly by Tamil people of the Indian subcontinent. It has official status in the Indian state of Tamil Nadu and in the Indian union territory of Pondicherry. Tamil is also an official language of Sri Lanka and Singapore...

 that is spoken in Kongu Nadu

Kongu Nadu

Kongu Nadu is a region comprising the western part of the Tamil Nadu India. The region is bounded on the west and north-west by the Karnataka state, on the west by the Kerala state, on the east by Tondai Nadu, on the south-east by Chola Nadu and on the south by Madurai regions of...

, which is the western region of Tamil Nadu

Tamil Nadu

Tamil Nadu is one of the 28 states of India. Its capital and largest city is Chennai. Tamil Nadu lies in the southernmost part of the Indian Peninsula and is bordered by the union territory of Pondicherry, and the states of Kerala, Karnataka, and Andhra Pradesh...

. It is also known as "Kangee".`

The name Kongu

Kongu

Kongu may refer to:* Kongu , a region in Tamil Nadu* Kongu Engineering College, an engineering college in Tamil Nadu* Toa Kongu, a fictional hero from the BIONICLE series.* Kongu Arts and Science College, an Arts college in Tamil Nadu...

 etymologically means 'border' in Sangam

Sangam

The Tamil Sangams were assemblies of Tamil scholars and poets that, according to traditional Tamil accounts, occurred in the remote past. Three assemblies are described...

 Tamil. Alternative theories seems to point at 'Ganga' as the source for the name. Gangeya (Kaangeyam) and Ganganadu are alternative historical names for the Kongu region.

The speciality of Kongu Tamil is the use of the alveolar R (ற) instead of retroflex T/D (ட) of standard tamil. For example 'ennuDaya' (mine) of standard Tamil is pronounced enRa in the Kongu dialect. Additionally the use of guttural nasal (ங்) is more prevalent in Kongu Tamil, leading to situations where the grammar of Kongu Tamil would not fit into the grammar of standard tamil (as laid down in authoritative treatises like Tolkappiyam

Tolkappiyam

The Tolkāppiyam is a work on the grammar of the Tamil language and the earliest extant work of Tamil literature. It is written in the form of noorpaa or short formulaic compositions and comprises three books - the Ezhuttadikaram, the Solladikaram and the Poruladikaram. Each of these books is...

 and Nannool). One of the examples is the use of ங் to end a word like வாங் "vaang", means 'come' expressed in a respectful tone, which in standard Tamil would be "vaanga".

Kongu Tamil also uses certain Tamil words that are unique to Kongu region and are not used in standard Tamil.