Provide an example of overextension in early word learning.

• A. Calling all four-legged animals 'dog'.
• B. Calling the family dog 'dog' and no other dogs.
• C. Calling a dog 'dog' for a dog in the book.
• D. Calling a dog 'dog' for a specific breed.

Answer: (A)

Overextension happens when a child uses a known word to refer to a broader group of objects than the word actually describes. The classic example is calling all four-legged animals “dog.” A child learns the word from one pet and then applies it to other animals like cats, horses, or cows, extending the label beyond its true category as a dog. This shows how vocabulary grows quickly, but the categories aren’t yet precise.

The other scenarios illustrate different patterns: using the word only for the family dog and no other dogs is an underextension, where the child narrows the meaning. Using the word for a dog that appears in a book is simply applying the label to a known instance and isn’t broadening the category. Calling a dog by its breed would still fall within a general label for dogs rather than extending the label to a broader, incorrect range.