1. Adjectives agree in gender and number with the noun they modify:
* Masculine singular: Use the adjective in its base form.
* Example: *un livre rouge* (a red book)
* Feminine singular: Add -e to the end of the adjective.
* Example: *une chemise rouge* (a red shirt)
* Masculine plural: Add -s to the end of the adjective.
* Example: *des livres rouges* (red books)
* Feminine plural: Add -es to the end of the adjective.
* Example: *des chemises rouges* (red shirts)
2. Adjectives generally come after the noun:
* Example: *une robe bleue* (a blue dress)
3. There are some exceptions:
* Adjectives of size, beauty, and goodness can sometimes go before the noun.
* Example: *un grand homme* (a tall man)
* Certain adjectives are always placed before the noun, such as:
* *beau* (beautiful)
* *bon* (good)
* *grand* (big)
* *petit* (small)
* *vieux* (old)
* When an adjective is used with a noun that is already preceded by a determiner (like "le", "la", "les"), it must come after the noun.
4. You can learn lists of common French adjectives online or in a textbook.
Remember: The placement of adjectives can sometimes affect their meaning. For example, "une bonne pomme" (a good apple) is a different concept than "une pomme bonne" (an apple that is good).
It's important to study French grammar and practice using adjectives in different contexts to get a good grasp of how they work.