Final answer:
Underextension is the tendency to apply a word too narrowly, while overextension is the tendency to apply a word too broadly. These tendencies are observed in language development.
Step-by-step explanation:
The tendency to apply a word too narrowly is called underextension. Underextension occurs when a child uses a word to refer to only a limited set of objects or situations, rather than all the appropriate instances. For example, if a child only uses the word "dog" to refer to their family pet and not other dogs, it would be considered underextension.
On the other hand, overextension refers to when a child uses a word too broadly, applying it to a wider range of objects or situations than is appropriate. For instance, if a child uses the word "dog" to refer to any four-legged animal, including a cat or a cow, it would be considered overextension.
Understanding these tendencies in language development can help us gain insights into how children acquire and use language.
Learn more about language development