How do adjectives work in French?

The first difference with English is that adjectives have to agree with the gender and number of the noun they describe. Concerning the gender, if the noun is masculine, the adjective has to be masculine. For instance: un petit garcon. If the noun is feminine, the adjective has to be feminine: une petite fille. Concerning the number, it follows the same rule. If the noun is singular, the adjective has to be singular. However, if the noun is plural, the adjective has to be plural: des petits garcons or des petites filles. To form a feminine adjective, you usually need to add an 'e' at the end of the word; but you do not need to add an extra ‘e’ if it is already a word ending with an ‘e'. However, there are some irregular words.

• The adjectives ending in ‘f’ become ‘ve’ in feminine
• The adjectives ending in ‘x’ become ‘se’ in feminine
• The adjectives ending in ‘er’ become ‘ère’ in feminine
• The adjectives ending in ‘on’, ‘en’, ‘el’, ‘il’ double the last letter and add an ‘e’ Other irregular adjectives do not follow rules, you need to learn them:
• Vieux - vieille
• Beau - belle
• Nouveau - nouvelle
• Roux - rousse
• Blanc - blanche. For plural adjectives, you simply add a ‘s’ at the end of the word. Moreover, another difference with english is the position of the adjective. Always before the noun in English, the adjective is mostly after the noun in French. For instance: une robe jaune; une jupe longue. However, some adjectives go before the nouns when they are short and common words. For instance: une grande fille; une vieille dame.