Final answer:
A conjunction postpones the execution of a sentence without changing it. It connects words, phrases, or clauses, indicating relationships between ideas and providing structure to complex and compound sentences. Commas, phrases, and clauses have different roles in sentence construction.
Step-by-step explanation:
The correct answer to the question is conjunction. A conjunction is a part of speech that connects words, sentences, phrases, or clauses. When used in sentences, conjunctions, such as 'and', 'or', and 'but', join together clauses to create compound or complex sentences. Suspensive conjunctions specifically can postpone the execution of a sentence. For instance, the coordinating conjunction 'but' in the sentence 'I wanted to buy the book, but the store was closed' connects two independent clauses and introduces a pause in the execution of the thought, which awaits the information after the conjunction.
Conjunctions do not change the actual meaning or 'sentence' in this sense of the individual clauses they connect; rather, they are used to join ideas and indicate relationships between those ideas. Phrases, on the other hand, are groups of words that function as a unit within a sentence without conveying a complete thought, thus cannot postpone the execution of a sentence's meaning on their own. Clauses, whether subordinate or independent, contain a subject and verb and contribute to the sentence's meaning, while commas are punctuation marks that indicate a pause or separation of ideas within a sentence.