Final answer:
The provided sentence is not complete as it is a run-on combining two independent clauses. Use a period or a semicolon to separate them into complete sentences, like 'Mr. Robertson is looking for an apartment. You should tell him this unit is vacant.' or 'Mr. Robertson is looking for an apartment; you should tell him this unit is vacant.'
Step-by-step explanation:
The question:
Is this a complete sentence? Mr. Robertson is looking for an apartment, you should tell him this unit is vacant.
The given sentence is not a complete sentence; it contains two independent clauses without proper punctuation to separate them, which makes it a run-on sentence. To correct this, you could use a period or a semicolon to separate the two thoughts: "Mr. Robertson is looking for an apartment.
You should tell him this unit is vacant." or "Mr. Robertson is looking for an apartment; you should tell him this unit is vacant." Both corrections provide a complete sentence with proper structure.
Complete sentences are crucial in writing for clarity and coherence. An example of a single independent clause being used as a complete sentence is "The subject is the implied pronoun you, which is usually omitted in orders or requests." This example demonstrates how a simple sentence can convey a complete thought effectively.