Almost all Singaporeans are bilingual since Singapore's bilingual language education policy promotes a dual-language learning system. Learning a second language has been compulsory in primary schools since 1960 and secondary schools since 1966. English is used as the main medium of instruction. On top of this, most children learn one of the three official languages (or, occasionally, another approved language) as a second language, according to their official registered ethnic group. Since 1 January 2011, if a person is of more than one ethnicity and their race is registered in the hyphenated format, the race chosen will be the one that precedes the hyphen in their registered race.