Republic Act (RA) No. 12027, which aims to discontinue the use of the Mother Tongue as the medium of instruction for Kindergarten to Grade 3 and make its implementation optional for monolingual classes, has lapsed into law following the non-action of President Marcos.

The measure lapsed into law on Oct. 10.

Under the new law, the medium of instruction shall revert to Filipino and English. The regional languages shall serve as auxiliary media of instruction.

Monolingual classes may continue using the Mother Tongue as a medium of instruction as long as it complies with the following requirements:

• Official orthography developed and published by the Komisyon ng Wikang Filipino (KWF)
• Officially documented vocabulary published by the KWF
• Literature on languages and culture
• Grammar book
• Availability of teachers in the school who speak and are trained to teach in the Mother Tongue

A monolingual class refers to a group of learners who speak the same Mother Tongue and are enrolled in the same grade level in a given school year.

The Department of Education (DepEd), in consultation with the KWF, shall develop a language mapping policy within one year of the law's effectivity.

Violations of the new law shall be subject to administrative sanctions.

The Mother Tongue became the instruction medium from kindergarten to the first three years of elementary education under the Enhanced Basic Education Act of 2013.