Which sentence correctly uses commas to separate a nonrestrictive modifier?

Question

The man, who owned the floral shop, watered the shop’s hanging plants.
The young child-who is my nephew- is the cutest three-year-old ever!
My friend John, who owns a chocolate Lab puppy, is getting ready to leave for a trip.
The student, who aced the test, was excused from completing the homework assignment.

Answer 1

The sentences that correctly use commas to separate a nonrestrictive modifier are:

1. The man, who owned the floral shop, watered the shop’s hanging plants.
2. My friend John, who owns a chocolate Lab puppy, is getting ready to leave for a trip.
3. The student, who aced the test, was excused from completing the homework assignment.

However, the second sentence, The young child-who is my nephew- is the cutest three-year-old ever!, incorrectly uses dashes instead of commas to set off the nonrestrictive modifier.

So the correct sentences with proper comma use for nonrestrictive modifiers are the first, third, and fourth options.