| Она видела перед собой затылок отца. | She saw the back of her father's head in front of her. |
| Затылок его был совершенно седой. | His hair was all grey in back. |
NB When the word затылок functions as a subject and does not have a descriptive modifier, the construction затылок у + Genitive is often preferred to (a) and (b), above: | |
| Затылок у него был совершенно седой. | His hair was all grey in back. |