I always get stuck between appositive and modifier. As first learner in writing, I need to distinguish them. What should I do?
The appositive is a noun or noun phrase that modifies another noun. The appositive follows directly after the noun, with a comma separating them. It is similar in placement and intent to the reflexive.
The tree, an oak, cast a long shadow at sunset.
The tree, an old oak, cast a long shadow at sunset.
The tree, an old knotted oak, cast a long shadow at sunset
Opposite the appositive, modifiers tend to come before the noun(s) they modify. Let's use the above example:
The old knotted oak tree cast a long shadow at sunset.
Appositive and Modifiers are two completely different elements that function in very different ways. Modifiers can occur in phrase structure, or they can be used to modify clauses. But an Appositive can never occur in Phrase structure, except in some cases where there is no comma before it.
Here is an example of an Appositive:
Yesterday I watched the opera 'Carmen'.
In most cases the Appositive is detached from a phrase with a comma:
My cat, Tom, is very naughty.
Here notice that my cat and Tom both refer to the same entity. And you can use either Tom or my cat without changing the meaning of the sentence.
My cat is very naughty = Tom is very naughty.
Here Tom is the Appositive.
Now consider the following sentence:
[The alarming fact that the ice is melting rapidly] is a cause of concern for the scientists.
The bracketed element – the alarming fact that the ice is melting rapidly – is a Noun Phrase (NP) that functions as the Subject (Complement) of the clause.
Let's analyze the NP structure. The head noun here is fact. The (WORD-CLASS: determinative) is a Determiner, and alarming (WORD-CLASS: adjective) is a Modifier. We can omit Modifiers like alarming without making the sentence ungrammatical in most cases. But of course the meaning might be affected.
The Complement of the head noun is that the ice is melting rapidly and in most cases it can't be omitted without making the sentence ungrammatical. Likewise, we can't omit the Determiner the because fact is a count noun.