Adjective Agreement:
Adjectives in French and Spanish need to agree in number and gender with the words they modify. What that means is, if something is feminine, the adjective is feminine. If something is masculine and plural, the adjective needs to be masculine and plural.
Examples:
Spanish Example: Mi padre es alto y mi madre es alta. OR mis padres son altos. (note when you have more than one person, if one is masculine, you use the masculine adjective form in the plural)
French example: Mon père est grand et ma mère est grande. OR Mes parents sont grands. (note when you have more than one person, if one is masculine, you use the masculine adjective form in the plural)
Adjective Placement:
When using adjectives in French or Spanish to describe something, put the adjective after the word for most adjectives. (The elephant pink rule)
Spanish Example:
The blond girl: la chica rubia
French example:
The blond girl: la fille blonde
NOTE: There are a handful of high use adjectives that can precede the word like good or bad, and a handful of adjectives that change their meaning depending on whether they precede or follow the word, such a poor or new, but you will get that information later on in your language study.
Describing Quantities
Also when using quantities, although they must agree like an adjective, they always come before the word.
Spanish example:
Many books: muchos libros
twenty-seven students: veintisiete estudiantes
French exmaple:
many books: Beaucoup de livres
twenty-five students: vingt-cinq étudiants