Question #ee7c2

1 Answer

The word "deadly" is functioning as an adjective in that sentence.

Explanation:

The adjective "deadly" is functioning as a predicate adjective (a type of subject complement) that restates the subject noun "chocolate" following the linking verb "can be".

A subject complement is a noun, a pronoun, or an adjective that follows a linking verb to restate the subject of the sentence.
A linking verb is a verb that acts as an equal sign; the subject is or becomes the object of that verb.
-- A noun or a pronoun functioning as a subject complement is called a predicate nominative.
-- An adjective functioning as a subject complement is called a predicate adjective .

"Although safe for humans to eat, chocolate can be deadly to both dogs and cats."
-- chocolate = deadly

The word "deadly" can also function as an adverb to modify a verb, an adjective, or another adverb; for example:
"A deadly serious situation occurred when his dog ate the chocolate."
-- The adverb "deadly" modifies the adjective "serious".