instruction given in two different foreign languages that are neither a learner´s mother language nor an official language used in the country

instruction given in both L1 and FL (a language that is neither a learner´s mother language nor an official language used in the country)

instruction provided in L2 and FL

instruction that combines L1 (a mother language; the first language, a native language) with L2 (a second language; the language of instruction that is not a learner´s mother language but is used as an official, state language in the country)

 two languages are used approximately equally in the curriculum with the aim of children becoming bilingual and biliterate which are incresingly found in the USA 

They can be found throughout the world, mostly in large cities of more than 80 countries. In these schools, fees are paid to receive private, selective, independent education

 language minority children use their native, ethnic, home or heritage language in the school as a medium of instruction and the goal is full bilingualism