euphemism

I am just grading an exam paper. One question includes the following:

In the following sentence, the word died occurs. Often, we use a euphemism to refer to something unpleasant such as death. Rewrite this sentence with a euphemism in place of died.

   My grandfather died last month.

A couple of students offered the following as their answer:

   My grandfather a euphemism last night.

Now, how many marks should I give to that?