What is the sentence structure

-1. Although Jim was wealthy, he was still unhappy.

Complex Sentence

Explanation:

This is a complex sentence.

Complex Sentence:

A complex sentence consists of at least one independent clause (one which conveys a complete meaning) and at least one dependent clause (one which does not offer a complete meaning when read alone).

The above given sentence starts with a dependent clause (Although Jim was wealthy) and ends with an independent clause (he was still unhappy).