General note: All the 'lah', 'leh', 'oi', 'har', 'aiya', etc. added to the dialogue are part of the Singlish vocabulary to accentuate the meaning of the sentence.

A levels: An examination held annually in Singapore, conducted jointly by Singapore's Ministry of Education and the University of Cambridge.

ACS: Anglo-Chinese School, one of Singapore's top high schools.

Chiarong, or 佳容: Chloe's Chinese name. The first character means "good, auspicious, beautiful" while the second means "appearance, form". So essentially, a good and beautiful girl.

Chio: Pretty in Hokkien.

Chiobu: Pretty girl in Hokkien.

CCA: Co-curricular activity. Used to be known as extracurricular activity, but the name is changed in Singapore. It's a non-academic activity that is required for all students to undertake as part of their education.

EC: eye candy. Meaning: someone you find superficially attractive to look at, but not necessarily crushing or interested romantically. It's a Singaporean slang used among Junior College students. It can also be used as a verb.
Example usage 1: "Who is your EC?" "Jon!"
Example usage 2: "Omg let me tell you a secret... I EC Jon."

HDB: Housing Development Board, Singapore's public housing. They are subsidized housing built and managed by the government.

Hokkien: A common Chinese dialect spoken in Singapore

Hyuna: Popular solo artist in South Korea.

Is it?: A variation of "Really?" Usually appended to a sentence.

Jay Chou: Jay Chou is the king of MandoPop.

JC: Junior College. High school equivalent in Singapore.

One: Sometimes added to the end of a sentence to emphasize it. It has Mandarin roots to it, and a Reddit discussion is linked here: https://www.reddit.com/r/singapore/comments/3t47t6/how_do_you_use_one_in_singlish/

Siao: Crazy in Hokkien.

Wah lao: A Hokkien curse word commonly used.