The Linguistics section of the Centre de recherches tsiganes at the Universite Rene Descarte arrived at the following divisions in the Romani language:

Romany in its original sense, which is spoken by the majority of Roma around the world, is further divided into three groups of dialects. These dialects have the basic Romany vocabulary and, except for loan-words from contact languages for modern life (television, truck-driver, etc.), there's a high level of comprehension between them.

The Balkan-Carpathian-Baltic group has a very well-preserved phonology (system of phonetics), and is further divided into:

the Old Balkan, or Arlijan, subgroup,

the Carpathian subgroup, and

the Baltic subgroup.

The Gurbet-Cerhan group is spoken exclusively in the Balkans.

The Kalderash-Lovar group which has gone through fairly considerable changes in the area of phonology, is the most geographically widespread, reaching from the Urals to California and Buenos Aires. This dialect, or group of dialects, has also been given the name Vlax Romany.

The Sinto-Manush dialects, are divided into Carpathian and Baltic subgroups and contain a large number of loan-words from Germanic languages. Even the morphology (system of word structure) of these dialects has undergone substantial changes, so that comprehension between speakers of these dialects and the preceeding ones is minimal.

Local dialects of other languages containing Romani words, are spoken by groups of Roma who lost their own language in efforts toward assimilation. The Spanish gitanos, for example, were persecuted in the 17th and 18th centuries and punished for using Romany, so that the Calo dialects have Romany words but Spanish grammar. Similar situations exist in Great Britain and some regions in Rumania. These dialects are completely incomprehensible for Roma of the other dialect groups.