a ship's doctor, is shipwrecked on the island of Lilliput
لماذا لم يقل doctor's ship
Jonathan Swift wrote other books, but nonewere as successful as Gulliver's Travels. Jonathan Swift died to 1745.
لماذا لم يقل none was مع العلم أن none يأتى بعدها الفعل جمع أيضا ولكن أليس المفرد أفضل
أرجو التوضيح

ship's doctor =the doctor who works on board the ship
doctor's ship = a ship owned by a doctor

none was is formal
none were is informal"