Here's why:
* Linking verbs connect the subject of a sentence to a noun or adjective that renames or describes the subject. They don't show action.
* In the sentence "The caterpillar becomes a butterfly," the verb "becomes" links the subject "caterpillar" to the noun phrase "a butterfly." It tells us that the caterpillar changes into something else.
Other common linking verbs include:
* be (is, am, are, was, were, been, being)
* seem
* appear
* feel
* look
* smell
* taste
* sound
* grow
* remain
* turn
Let me know if you have any other questions!