Final answer:
The clause 'While we were attending the wedding' is a dependent clause because it cannot stand alone as a complete sentence and begins with a subordinating conjunction 'while'.
Step-by-step explanation:
The clause 'While we were attending the wedding' is a dependent clause. As a group of words that contains a subject and a verb, it cannot stand on its own as a complete sentence because it starts with 'while', which is a subordinating conjunction. Expressions that start with subordinating conjunctions, like 'while', 'because', 'if', and others, are dependent on a main clause to provide a complete thought.
For example, 'While we were attending the wedding, the ceremony was beautiful.' In this sentence, the clause 'the ceremony was beautiful' is an independent clause that stands on its own, whereas the introductory clause is dependent and requires the independent clause to form a complete sentence.