What structure is used in the sentence it was a gloomy day when you found out your teamlost debate?

The sentence "It was a gloomy day when you found out your team lost the debate" uses a complex sentence structure.

Here's why:

* Independent Clause: "It was a gloomy day"

* Dependent Clause: "when you found out your team lost the debate"

The dependent clause, starting with the subordinating conjunction "when," modifies the independent clause by telling us when the day was gloomy.

Note: There is also a prepositional phrase within the dependent clause: "your team lost the debate".