Grade school 就是中、小学,在加拿大还有Grade 13。
K1-K3 是幼儿园。
Pre K 就是学前。
pre-K = preschool (school before kindergarten)
K = kindergarten (= the year before first grade; essentially 0th grade)
This sounds like Canadian English: Americans say \"12th grade\"; Canadians
say \"grade 12\"