Learn Hardcore Turkish: Tuzak ustaca kurulduğu için adım atmak zorlaştı. - Because the trap was cleverly set, it became hard to step forward.

ustaca is an adverb formed from the noun usta (“master, expert”) plus the adverbial suffix -ca (sometimes written -ça). It means “masterfully,” “skillfully,” or “cunningly.” Here it modifies kurulduğu, telling us how the trap was set.

How does the suffix -duğu work in kurulduğu, and what does it do grammatically?

The root verb is kurmak (“to set, to install”). In kurulduğu, three things happen:

-ul marks the passive voice → kuruldu (“was set”).
-du is the simple past tense suffix → kuruldu (“was set”).
-ğu (a variant of -dığı) is the nominalizing/relative participle suffix with third-person reference → kurulduğu (“that it was set”).
This turns a finite verb into a noun-like clause you can attach için to, so it literally means “because it was set.”

How does kurulduğu için express “because the trap was set,” and how is this different from using çünkü?

-dığı için is a suffixal-clause marker: you take kurulduğu (“that it was set”) and add için (“for, because”) to create an adverbial clause of reason.
In contrast, çünkü is a standalone conjunction meaning “because,” usually placed at the beginning of the causal clause.
Example:
• Tuzak ustaca kurulduğu için…
• Çünkü tuzak ustaca kuruldu…
Both mean “because the trap was cunningly set,” but -dığı için attaches directly to the verb and keeps the sentence flow tighter.

What does adım atmak zorlaştı literally translate to, and how is adım atmak analyzed?

Literally, adım atmak is “to take a step” (adım “step,” atmak “to throw/make”). In context it means “to advance one’s foot” or simply “to step.”
zorlaştı is the past-tense form of the verb zorlaşmak (“to become difficult”). So adım atmak zorlaştı = “taking a step became difficult.”

What is the grammatical function of the entire phrase Tuzak ustaca kurulduğu için in the sentence?

Tuzak ustaca kurulduğu için is an adverbial clause of reason (a subordinate “because…” clause). It modifies the main clause adım atmak zorlaştı, explaining why stepping became difficult.

Why is tuzak in the nominative case here, and when would it take a case ending?

As the subject of the passive verb kurulduğu within the reason clause, tuzak stays in the nominative. If you switched to active voice—making someone the subject and tuzak the object—you’d mark it with accusative -ı, e.g., Adam tuzağı ustaca kurduğu için… (“Because the man cunningly set the trap…”).

Could you express this idea in the active voice with an explicit agent? How would the sentence change?

Yes. To name the setter, you switch to active and mark tuzak as object:
“Adam tuzağı ustaca kurduğu için adım atmak zorlaştı.”
Here:
• Adam = “the man” (subject)
• tuzağı = “the trap” (object, accusative)
• kurduğu için = “because he set” (relative participle + because)
• adım atmak zorlaştı = “taking a step became difficult.”
This makes the agent explicit rather than leaving the action passive and agentless.