The study of a second language would become compulsory in all government or government-aided schools of all language streams, it was announced in November 1965.
The policy, which took effect the following year, 1966, marked the start of Singapore's bilingual education policy. Under the change, all students would also be required to offer a second language for the school certificate examination from 1969.
The move led to the introduction of the teaching of three mother tongues - Chinese, Malay and Tamil - in English-medium schools; and English in the Chinese, Malay and Tamil medium schools. It also paved the way for English to become the common working language.
Announcing the policy at a Teachers Training College graduation ceremony at Victoria Theatre in 1965, Education Minister Ong Pang Boon said: "The breaking down of the language barrier, inimical to racial unity, must be further intensified to strengthen the foundations of a multiracial nation.
"It is in the schools that we must intensify our efforts."
The move was also to ensure that future school-leavers would be proficient in at least two languages, and better serve Singapore's multiracial and multilingual society.
"Similarly, all the institutions of higher learning in the state should proceed in earnest to provide facilities for the study of languages, particularly for students who are monolingual," he said.
The teachers' college played a vital role in raising the standards of the second language in schools, he said, as it was where a large number of language teachers would be trained to meet demand.
Besides training new language teachers, special training courses for the more than 1,000 existing language teachers must be completed in the next few years, he said.
In Parliament in 1966, Mr Ong gave an update, noting that all 114 government and government-aided secondary schools offered a second language.
In the 1960s and up to the 1980s, parents could enrol their children in vernacular schools. But these were gradually phased out as more children went to English-medium schools. The Government announced that by 1987, all students here would be taught in English.
The bilingual language policy led to a shift in the predominant language spoken at home. English became increasingly spoken by Singaporeans at home; Mandarin also gradually replaced the use of Chinese dialects in the home.
This week in 1965: A look back at the events that shaped Singapore 50 years ago In the 1960s and up to the 1980s, parents could enrol their children in vernacular schools. But these were gradually phased out as more children went to English-medium schools.