Learn Turkish: Bundan daha tekdüze bir iş var mı? - Is there a more monotonous job than this?

It means "monotonous" or "uniform" and is a compound word formed from tek (single) and a derivation of düz (flat, straight). You can think of it literally as "single-level" or "unvarying," which perfectly describes a mundane routine.

Why is bir placed after the adjectives instead of at the beginning of the phrase?

In Turkish, the indefinite article bir (a/an) almost always sits directly in front of the noun, after any adjectives. Even with a comparative block like daha tekdüze (more monotonous), the rule holds: adjective + bir + noun, giving us daha tekdüze bir iş.

Why does bu take an -n- buffer in bundan instead of the usual -y-?

Demonstrative pronouns like bu, şu, and o always take the buffer letter -n- before case endings, unlike regular nouns ending in vowels which usually take -y-. Adding the ablative case (-dan) to mean "than this" gives us bu-n-dan.

Can I use tekdüze to describe a boring person?

Usually not. Tekdüze is almost exclusively used for systems, routines, tasks, or lifestyles that lack variation. To call a person boring, you would use a word like sıkıcı.