Final answer:
To label each word group as complete, fragment, or run-on, we need to understand the characteristics of each type of sentence. Complete sentences have a subject and predicate, fragments are incomplete sentences, and run-on sentences lack proper punctuation between clauses. Let's label each word group accordingly.
Step-by-step explanation:
To label each word group as complete, fragment, or run-on, we need to understand the characteristics of each. Complete sentences express a complete thought and contain both a subject and a predicate. Fragments are incomplete sentences and are missing either a subject or a predicate. Run-on sentences occur when two or more complete sentences are not separated by any punctuation. Let's label each word group:
The red car is a complete sentence. Running across the field is a fragment. Since the game started is a fragment. We are best friends is a complete sentence. I forgot to text my mom is a complete sentence. We should go study; the test is tomorrow! is a run-on sentence. Grammar is easy, people just need to memorize the rules is a complete sentence. Run-ons come from compound sentence errors and we should proofread more closely is a complete sentence.