It is a common experience for the foreigner learning Tamil to discover to his dismay that after months of study with grammar and reader and munshi he is able to understand scarcely anything of the language spoken around him. In the villages and the fields, in the bazaars and on the highroads he hears a language spoken which he finds it hard to believe is the language of his study. The fact is that the language as it is spoken by the great majority of the Tamil people differs considerably from the language as spoken by the educated. And even the educated tend to reserve correctness for the written word and the speech of formal occasions, and lapse readily under more familiar circumstances into the dialect of the masses. The deviations of the dialect from standard pronunciation may be discussed under the two headings of omissions and substitutions—the dropping of a consonant or a syllable, and the substitution of one vowel or consonant for another.

One of the most noticeable features of common speech is the dropping of the final consonant. The consonants chiefly affected are m, n, ḷ, r, and l. When m and n disappear, the vowel is nasalized. Thus nām sahhiliyar becomes sakkiliyar; nān kāvaṛlcaran becomes kāvakkarã.