A possessive form of a word is one that shows ownership, origin or a relationship tie. In English most possessives are shown by "apostrophe s". Examples are * Carol's bike * New York's skyline (some people say it's better to show the relationship of objects by spelling it out like "skyline of New York") * Mike's sister-in-law These could all be written out in other ways, such as * the bike owned by Carol * the skyline of New York * the sister-in-law of Mike