sentences:  Estimates of the numbers of second language and foreign-language English speakers vary greatly from 470 million to more than 1 billion, depending on how proficiency is defined.Linguist David Crystal estimates that non-native speakers now outnumber native speakers by a ratio of 3 to 1.In Kachru's three-circles model, the "outer circle" countries are countries such as the Philippines, Jamaica, India, Pakistan, Singapore, Malaysia and Nigeria with a much smaller proportion of native speakers of English but much use of English as a second language for education, government, or domestic business, and its routine use for school instruction and official interactions with the government.