Words like each, every, everybody, nobody, anybody, and neither are singular. They talk about one person or thing.
Every passenger has a bag.
• Every book on the shelf is new. NOT Every book on the shelf are new.
(There are lots of books on the shelf, but we are thinking of them as separate books, not as a collection)
• Each invoice must have its own number.
• Neither of my shirts was clean. NOT Neither of my shirts were clean.
Remember: Each and every is one.
Every book in the lorry is big.