The sentence "I just needed someone to listen." is a complete sentence because it contains a subject ("I"), a verb ("needed"), and a complete thought. It expresses a clear idea without requiring additional information.
Option 2: Run-on
A run-on sentence occurs when two or more independent clauses are joined without proper punctuation or conjunctions. This sentence does not fit that description, as it is a single independent clause.
Option 3: Fragment
A sentence fragment is an incomplete sentence that lacks a subject, a verb, or a complete thought. This sentence is not a fragment because it includes all necessary components to form a complete sentence.