Hello! I'm Elizabeth O'Brien, and my goal is to get you jazzed about grammar.
What is an appositive?
Do you know what appositives are? They are nouns that rename other
nouns, and we use them to give more information about someone or
something that we've already named. Let's look more closely at what they are and see how they are diagrammed.
Esther is the subject of the sentence. It is also a noun. The word sister is renaming Esther. It is a noun that gives us more information about Esther. Both words are referring to the same person.
So, sister is a noun that renames another noun, Esther.
Do you know much about phrases? Phrases are groups of words, without both a subject and a verb, that come together to act as one part of speech.
Esther, my sister with dark hair, sang a song.
The appositive is the single word that is doing the renaming (sister).
The phrase is that single word plus all of the words that are modifying it (my sister with dark hair).
Nonessential or Essential? (+ How to Punctuate Them)
There are two types of appositives (nonessential and essential), and it's important to know the difference because they are punctuated differently.
Nonessential - Use Commas
Most are nonessential. (These are also called nonrestrictive.) That means that they're not an essential part of the sentence, and sentences would be clear without them. Set these apart from the sentence with commas.
My sister, a French teacher, studied in France during high school.
My mom, a talented woman, recorded a lullaby CD.
My husband, David, is allergic to cats.
Essential - Don't Use Commas
Some are essential to the meaning of the sentence. (These are also called restrictive.) If these weren't in the sentence, the meaning of the sentence would be unclear.
The movie Green Book won the award for best picture.
The author Victor Hugo was born in France.
Do you see how we need those in order to understand the meaning of those sentences? Without them, we wouldn't know which movie or author the sentence was referring to.