Final answer:
A sentence fragment is marked by an 'F' and corrected by adding a main clause to complete the thought. The updated sentence should include a subject and verb, forming a complete sentence.
Step-by-step explanation:
When evaluating if the words form a complete sentence or a sentence fragment, one should first identify if there's a subject and a verb present and whether the clause can stand alone as a complete thought. A complete sentence would be indicated with an "S," while a sentence fragment, which is a group of words that lacks a subject, a verb, or does not express a complete thought, would be marked with an "F." Sentence fragments often occur when there is a subordinating word such as 'since' or 'because' but no main clause to finish the thought.
To correct this, you can often combine the fragment with a related sentence to form a complete one.
For example, the phrase "since he is so curious" is a fragment because it lacks a main clause. It could be corrected to "Since he is so curious, Richard asks his mom many questions."
This corrected version forms a complete sentence with both a subject (Richard) and a verb (asks), and it expresses a complete thought. Moreover, when editing sentences for comma usage, ensure that it clarifies the meaning without creating run-on sentences or comma splices.