Here's why:
* Linking Verbs: Connect the subject of a sentence to a noun, pronoun, or adjective that renames or describes the subject. They don't show action. Examples: *is, are, was, were, seem, become, appear*.
* Prepositions: Show the relationship between a noun or pronoun and another word in the sentence. They often indicate location, direction, or time. Examples: *on, in, at, to, from, by, with*.
Examples:
* Linking Verb: "The sky is blue." (Blue describes the sky)
* Preposition: "The cat sat on the mat." (On shows the location of the cat)
While prepositions can sometimes appear in a sentence with a linking verb, they are not the linking verb themselves. For example:
* "She is in the library." (In is a preposition showing location, not a linking verb.)
Let me know if you have any other grammar questions!