Thank you for your reply, Sir. But another question remains, I think. That is, if parentheticals can behave as either modifiers, intensifiers, interrupters, or interjections, does it mean liberty for writers to place parentheticals where they want to?
Positioning parentheticals in a sentence is done on a case to case basis, based on functionality, logic, and clarity.
When a parenthetical is used as a modifier, it obviously should be positioned right after the word or phrase it modifies, as in this example:
“Alicia,
a popular cheerleader in high school, doesn’t want to have the same extracurricular involvement in college.”
In that sentence, “a popular cheerleader in high school” is an appositive that functions as a parenthetical because it’s inserted in the passage as an amplifying or explanatory phrase.
That sentence, of course, can also be constructed this way:
“
A popular cheerleader in high school, Alicia doesn’t want to have the same extracurricular involvement in college.”
In that front-end position, though, “a popular cheerleader in high school” isn’t a parenthetical because it’s not an inserted element in the sentence. It’s simply a front-end adjective phrase.
Positioning is even more crucial in the case of an interrupter as a parenthetical:
“The scholarly Joanna—
of all people!—wants to be college cheerleader.”
Obviously, that interrupter doesn’t work—it doesn’t do the interruption job—when placed at the tail end of the sentence:
“The scholarly Joanna wants to be college cheerleader—
of all people!”
When a parenthetical is an intensifier, it obviously should immediately follow the noun being intensified, as in the following example:
“George—
our very own George!—got the state scholarship!”
In the case of an interjection, the parenthetical expression should break into the idea being expressed, as in the following example:
“Our longtime partner—
alas!—has abandoned us!”
It doesn’t serve its purpose positioned at the tail end of the statement:
“Our longtime partner has abandoned us,
alas!”