Center for Writers - Resources


Restrictive elements (also called essential elements) and nonrestrictive elements (also called nonessential elements) function as modifiers in sentences. A modifier is a word or group of words that describes or limits other words, phrases, and clauses.

        Restrictive elements are essential to the meaning of a sentence.

                    The man who wore the yellow hat waved to us from the tour bus.
                            [This information identifies this man in particular and sets him
                            apart from other men on the same bus.]
                    The woman sitting on the beach under the umbrella was reading
                            Tolstoy and eating a popsicle.  [This information is essential
                            because it identifies which woman on the beach was doing this.]

                   Restrictive elements are not set off by commas.

        Nonrestrictive elements are not essential to the meaning of a sentence.

                    Miss Trevor, with whom I'd graduated from high school, is a successful
                            businesswoman.  [This information is unnecessary to the reader's
                            understanding that Miss Trevor is successful.]
                    The envelope, which had had no return address, was yet sitting
                            on the table at the foot of the staircase.  [It is unnecessary for the
                            reader to know that the envelope had no return address to
                            acknowledge its location in the house.]

                   Nonrestrictive elements are set off by commas.