There was:单数
There was a book on the desk.
There was an apple in the bag.
There was a knife in his hand.
There was a new dictionary in the table.
There was a man on the street.
There were:复数
There were some books on the desk.
There were some apples in the bag.
There were some knives in his hand.
There were some new dictionaries in the table.
There were some men on the street.