(L.6.2.b) The Scroll of Setting Off Nonrestrictive Modifiers

The ability to use punctuation (commas, parentheses, dashes) to set off nonrestrictive/parenthetical elements

The Scroll of setting off nonrestrictive modifiers

L.6.2.B50xp

Non-restrictive vs. restrictive modifiersA non-restrictive modifier adds information that is not essential to our understanding of the sentence; if we remove it from the sentence, the basic meaning of the sentence does not change.A restrictive modifier identifies, or limits the reference of, the noun it modifies.Example of a non-restrictive modifier:The statue of his mother by Joseph Smith, dated 1894, sold for over a million dollars.The date of Joseph Smith's statue can be removed from the sentence without altering its meaning:The statue of his mother by Joseph Smith sold for over a million dollars.Example of a restrictive modifier:The painting dated 1894 is a forgery; the one dated 1892 is genuine.The phrases "dated 1894" and "dated 1892" cannot be detached from the sentence without making the meaning unclear:The painting [which one?] is a forgery; the one [which one?] is genuine.

Non-restrictive vs. Restrictive Modifiers

Commas with Nonrestrictive ModifiersA modifying word, phrase, or clause following a noun is set off by commas if it presents information which is not essential to identify the noun or the meaning of the sentence.This is called a nonrestrictive modifier, i.e., it does not restrict the meaning of the noun or sentence.Example: Any student not sitting down will get detention.(This takes no comma because the phrase not sitting down is necessary to identify the noun. Remove it, and you get something very different: "Any student will get a detention.")Example: Marcia Gomes, who was not sitting down, just got a detention.(Here the person is named specifically. We know whom the sentence is about. The clause who was not sitting down does add information, but it is not necessary to identify the noun it modifies. Drop the clause and we still know who got the punishment: "Marcia Gomes just got a detention.")Sometimes, the punctuation may depend on the situation. For example, if I have just one sister, or the reader already knows whom I am talking about, this sentence is correct:My sister, Martha, is a nurse.However, if I have more than one sister and it is not otherwise clear whom I am talking about, her name is essential to identify the sister.My sister Martha is a nurse.Or perhaps to make it clearer:My sister Martha is a nurse; my sister Marianne is a teacher.

Dashes with Nonrestrictive ModifiersCommas are normally used to set off nonrestrictive modifiers.However, nonrestrictive modifiers can be set off by dashes for emphasis or if the modifiers contain commas or other punctuation that could confuse the reader.Incorrect: Some expensive films, Heaven's Gate, for example, have been big flops. (Relationships not clear)Correct: Some expensive films--Heaven's Gate, for example--have been big flops. (Modifier itself has a comma.)