Which word from this sentence is a proper noun?I told Kelly she could borrow my wellies.

The proper noun in the sentence "I told Kelly she could borrow my wellies." is "Kelly."

Explanation

A proper noun is a specific name that identifies a particular person, place, or organization, distinguishing it from common nouns that refer to general items. In this case, "Kelly" is the name of a person, which qualifies it as a proper noun. Common nouns include words like "wellies," which refer to a type of footwear, and are not capitalized unless they start a sentence. Proper nouns are always capitalized, indicating their unique status in identifying individuals or entities. Hence, in analyzing the sentence, we see that "Kelly" is clearly the proper noun, while the rest of the words serve different grammatical functions, such as verbs and common nouns.