people who are more or less proficient in both languages but will not necessarily pass for a native speaker in both languages

a person who is a native speaker in one and is capable of understanding but not speaking another language

a person who passes in any situation in both languages for a native speaker

a person nos strong in either/any language

a person who has two separate linguistic systems and can handle each of them easily, usually because each parent has and speaks in a different mother tongue to the child

a person who is more proficient in one of the two languages

 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