Learn French: C'est un livre parfait.

In French, you only add an -e to a regular adjective if it describes a feminine noun. Because un livre (a book) is masculine, the adjective parfait stays in its base masculine form without the -e.

Why does parfait come after the noun instead of before?

Most adjectives in French are placed after the noun they describe. So, instead of 'a perfect book', French structures it as 'a book perfect' (un livre parfait). Only a small group of common adjectives (like big, small, or good) go before the noun.

Do I pronounce the 't' at the end of parfait?

No, the final 't' is silent. However, if you were describing a feminine noun, you would add an -e to make it parfaite. That added -e makes the 't' suddenly pronounced!

Why do we use C'est instead of Il est for 'It is'?

Use C'est when 'It is' is followed by a noun with an article, like un livre. You only use Il est when the pronoun is followed directly by an adjective, for example: Il est parfait (It is perfect).