Questions & Answers about İki tane açık kutu var.
Why is the word kutu (box) in the singular form when the English translation says "boxes"?
In Turkish, whenever you use a specific number (like iki) before a noun, that noun must remain in its singular form. Saying iki kutular is incorrect.
What does tane mean, and is it mandatory?
tane translates to "item" or "piece." It is a counting word used when counting physical objects. You don't absolutely have to use it (you could just say iki açık kutu), but adding tane after numbers sounds much more natural in everyday Turkish.
Why does açık (open) come after tane?
I learned that var means "there is". Why does it mean "there are" here?
var just points out that something exists, so it handles both "there is" and "there are." Since the sentence talks about two boxes (iki tane), we naturally translate it to "there are" in English.