As an insult sometimes, people here use the abbreviated form kinder. Expressions like these are common: 1) What? You still don't know how to spell your name?! I may send you back to kinder! 2) In a language class for college students, they discuss simple vocabulary and grammar. When the students fail to understand, the professor may say: It's like [a lesson for] kinder! The other common expression is grade one which you can use to replace kinder in my sentences.