Learn Turkish: Kutu dolap kadar derin mi? - Is the box as deep as the cabinet?

The postposition kadar means "as much as" and always comes directly after the noun you are comparing things to. Here, dolap kadar means "as much as the cabinet." When you add the adjective derin (deep) right after it, it translates to "as deep as the cabinet."

Why doesn't dolap have any case endings before kadar?

When you use regular nouns with kadar to make a comparison, they stay in their plain dictionary form. That is why it is just dolap (cabinet) and not dolabı or dolaba. Just remember that this rule changes for personal pronouns, which usually take the genitive ending (like benim kadar).

How does the word order for comparisons differ from English here?

In English, the structure is broken up: "as [adjective] as [noun]". In Turkish, you group the comparison together after the subject. The subject kutu (the box) comes first, followed by the standard Turkish formula for equality: [Noun being compared to] + kadar + [Adjective].

Why is the question particle mi used here instead of mı or mu?