The underlined part of the sentence is a dependent clause, as it cannot stand alone and is introduced by the subordinating conjunction 'before.'
To identify independent and dependent clauses, we need to understand that an independent clause is a group of words that can stand alone as a sentence because it expresses a complete thought. A dependent clause, on the other hand, cannot stand alone as a complete sentence because it does not express a complete thought and is usually introduced by a subordinating conjunction.
In the sentence 'Please wear your uniforms before you enter the school compound,' the underlined part 'before you enter the school compound' is a dependent clause (DC). It cannot stand alone as a complete sentence as it is introduced by the subordinating conjunction 'before,' indicating that this clause is providing additional information to the main clause. The main clause 'Please wear your uniforms' can be an independent clause because it can stand on its own as a complete instruction.