Possessive adjectives describe to whom or to what something belongs. There is one possessive adjective for each grammatical person.
Possessive adjectives do not change according to the number of items belonging to the person.
|singular noun||plural noun|
|his book||his books|
|her book||her books|
Its is the possessive adjective for things. Note that there is no apostrophe: difference between its and it’s.
|The hotel is new. Its vestibule is large.|
|The hotel is new. Its rooms are expensive.|
|Their dream is unrealistic. (Tom and Sue’s dream)|
|Their dreams are unrealistic. (Tom and Sue’s dreams)|
Note that the number of dreams does not matter. Their is used because the dream(s) belong to more than one person.
With a list of things belonging to the same person, only use one possessive adjective.
|his brother and sister|
|my mother and father|
|our tables, chairs, and lamps|