Original sentence: Also in Singapore, "mother tongue" refers to the language of one's ethnic group regardless of actual proficiency, while the "first language" refers to the English language, which is the lingua franca for most post-independence Singaporeans due to its use as the language of instruction in government schools and as a working language
Edited sentence: Also in Singapore, "mother tongue" refers to the language assigned to one's ethnic group regardless of actual proficiency, while the "first language" refers to the English language, which is the lingua franca for most post-independence Singaporeans due to its use as the language of instruction in government schools and as a working language