The Indo-European languages include some 449 (SIL estimate, 2018 edition) language families spoken by about or more than 3.5 billion people (roughly half of the world population). Most of the major languages belonging to language branches and groups of Europe, and Western and southern Asia, belong to the Indo-European language family. Therefore, Indo-European is the biggest language family in the world by number of mother tongue speakers (but not by number of languages in which it is the 3rd or 5th biggest). Eight of the top ten biggest languages, by number of native speakers, are Indo-European. One of these languages, English, is the de facto World Lingua Franca with an estimate of over one billion second language speakers.