The product of seven years of compilation from the work of nearly two hundred world-renowned scholars in linguistics. The volume explores the structure, history and culture of 191 languages worldwide, with the aim of providing both the general public and linguistics experts with an authoritative source of rich, structured data on the world's major ethnolinguistic groups.

As a general rule, Facts About the World's Languages covers languages spoken by two million or more people. The volume does, however, make exceptions: such noteworthy ancient languages as Latin, Ancient Greek, Classical Chinese, Akkadian, Tocharian, Sumerian, Coptic, Ge'ez, Punic, Etruscan, Biblical Hebrew, Pali, and Sanskrit are included for their importance in early linguistic scholarship and in the development of many other languages. Additionally, some languages with smaller populations are featured to represent less frequently described language families and to give a broader typological perspective: Nivkh, Creek, Navajo, Cherokee, Eskimo, Warlpiri, and Arapesh among them.

Though linguistics is a highly technical discipline, the volume describes each language in words a student or layperson can comprehend. Technical terms that are indispensable to a thorough understanding of the subject are defined in the volume's glossary.