Which example would be most effective in helping students understand how compound words are formed?

The most effective example for helping students understand how compound words are formed is the one that includes words like "sunshine," "homework," and "butterfly." Each of these words is created by combining two separate words, which illustrates the concept of compound words clearly.

For instance, "sunshine" consists of "sun" and "shine," "homework" combines "home" and "work," and "butterfly" merges "butter" and "fly." By providing these specific examples, students can visually and conceptually grasp how two distinct words come together to form a new idea or meaning, thereby reinforcing their understanding of compound words.

In contrast, the other options consist of words that do not highlight the formation of compound words effectively. The second option lists singular nouns that do not combine to create new meanings, while the third consists of action verbs, which also do not form compounds. Lastly, the fourth option contains words that are all individual nouns that do not illustrate the concept of combining two different words with distinct meanings. Overall, the first option serves as the best model for teaching the concept.