Breakdown of El libro no es nuevo.
ser
to be
el libro
the book
nuevo
new / another, different (before the noun)
no
no / not
Questions & Answers about El libro no es nuevo.
Why is "no" placed before the verb "es"?
In Spanish, making a sentence negative is very straightforward: you just put no directly in front of the verb. While English says "is not", Spanish uses no es (literally "not is").
Why do we use es instead of está for "is" in this sentence?
We use es (a form of the verb ser) because being new or old is considered a defining characteristic of the object. Even though a book will eventually get old, describing its age as a trait always requires ser instead of estar.
Why does the word for new (nuevo) end in an -o here?
Adjectives in Spanish have to match the gender of the noun they describe. Because el libro (the book) is a masculine noun, nuevo takes the masculine ending -o. If we were talking about a feminine noun, like a house (la casa), it would change to nueva.