WHEN YOU IDENTIFY THE MAIN ACTION, THEN YOU IDENTIFY THE SUBJECT NOUN. 'CAUSE THE SUBJECT NOUN IS THE PERSON THAT DOES THE ACTION. BUT, YOU HAVE HAVE TO BE AWARE ABOUT THE "APPOSITIVES" AND THE "FRAGMENTS" WHICH MAY GIVE YOU A "FALSE SUBJECT NOUN". FOR INSTANCE: "As soon as I get there and I see her, my heart and I will talk". AS SOON AS I GET THERE AND I SEE HER, (APPOSITIVE OR FRAGMENT) MY HEART AND I (SUBJECT NOUNS) (1ST PERSON OF PLURAL) WILL TALK. (MAIN ACTION).
Study is a verb. It describes an action.
Jump is a verb. It describes an action.
Acquire is a verb. It describes an action.
Wobble is a verb. It describes an action.
Fidgeting is a verb. It describes an action.
The word "glum" is an adjective. It describes someone who is moody or sullen.
A predicate noun is a a sub category inside a noun, which is a part of speech itself. It is simply a noun in the predicate.
adjective
The part of speech that describes a noun is called an adjective. Adjectives are words that modify or describe nouns by providing more information about their characteristics, qualities, or attributes.
"Taciturn" is an adjective. It describes someone who is reserved or uncommunicative in speech.
The word faithful is an adjective. It describes someone who is loyal.
Study is a verb. It describes an action.
Jump is a verb. It describes an action.
Sandwich is a noun. It describes a thing.
Persuaded is a verb. It describes an action.
Acquire is a verb. It describes an action.
Jumps is a verb. It describes an action.