Her boyfriend Nick met Jennifer at the hospital.
David and his father James managed to save their company from going bankrupt.
NOT A TEACHER
(1) I am shocked! Without the commas, the sentence means that she has more
than one boyfriend!
(2) And without the commas, it appears that David has more than one father!
My friend Tony speaks French, not my friend Mona. (I have at least two friends, Tony and Mona.)
My friend, Tony, speaks French. (I have only one friend. )
Student or Learner