Where does “từng lớp” come from?

từng lớp (Vietnamese) comes from Vietnamese lớp — a layer; grade; school year; a class.

Ancestry of “từng lớp”, step by step

từng lớp traces back through two separate lines of ancestry.

via Vietnamese lớp

StepLanguageWordMeaning
1Vietnameselớpa layer; grade; school year; a class

via Vietnamese từng

StepLanguageWordMeaning
1Vietnamesetừngonce; every; each; quantity; amount
Every word from Vietnamese lớp