Learn French: C'est une histoire merveilleuse.

The base (masculine) form of this adjective is merveilleux (wonderful). Because histoire (story) is a feminine noun, the adjective must also be feminine. In French, adjectives ending in -eux change to -euse in the feminine, making it merveilleuse.

Why is merveilleuse placed after histoire?

In French, most adjectives are placed after the noun they describe. Only a small group of short, common adjectives (describing Beauty, Age, Goodness, and Size) go before the noun. Since merveilleuse does not belong to that group, it follows the standard rule and comes after histoire.

Since histoire is feminine, why do we use C'est instead of Elle est?

We use C'est (meaning it is or this is) when introducing a noun accompanied by an article like un or une. Because we are introducing the noun phrase une histoire merveilleuse, we must use C'est. If we were only using the adjective, like "It is wonderful," we would say Elle est merveilleuse.

Is there a connected sound (liaison) between C'est and une?

Yes! When spoken naturally, the usually silent -t at the end of C'est connects to the vowel at the start of une. It is pronounced together, sounding a bit like "say-toon".