In this article, the using of some vernaculars in Iran based on the census of 1365 and the sampling of 1372 has been scientifically studied. Then, the statistic results of the research subjects speaking these
vernaculars or Persian have been shown through various tables.
For instance, it has been presented that the percentage of those
who did not know Persian was 17.3% in 1365 and 12.7% in 1372. This
can be compared with the percentage of illiterates in each province. Then, it may be concluded that the more the percentage of illiterates in each Province, the inhabitants of which speak a vernacular, is, the more the percentage of those who do not know Persian in that province is and vice versa.
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