As with the English language, French includes description words, otherwise known as adjectives. Like with various parts of speech, both languages share similarities in the use of adjectives, while being very different in others.
Your language learning software can probably cover this in greater detail. If you want to get an overview, though, the following list should walk you through the major differences.
Masculine and Feminine. Like many facets of the French language, adjectives frequently have masculine and feminine forms. This is a big departure from the English language, where adjectives are usually gender-free. In English, in fact, even words normally associated with one gender can be used to describe the other (e.g. “a manly girl” and “a pretty boy”).
Different Singular and Plural Forms. Unlike English where adjectives don’t have singular and plural forms, it’s a trait common in the French vernacular. Pronunciation usually have similarities, but spelling is often widely different.
Adjective Placement. In French, adjectives usually come after the noun. That’s in direct contrast with English where adjectives almost always precedes the subject (e.g “a tall and slim girl”), except on occasion (e.g. “a girl taller than me”).
Comparatives And Superlatives. There are no suffixes in French to easily present comparative and superlative forms of an adjective. In English, this is easily done by adding -er and -est to description words. Instead, comparison usually has to be integrated into the statement itself.