Usually adjectives come in masculine and feminine flavors and reflect the gender of the noun they describe. Normally masculine adjectives end in an -o and feminine adjectives end in an -a.

Some adjectives are invariable. They are the same regardless of whether they describe a masculine or feminine noun. These end in an e or consonant.

If a noun is plural then the adjective is also plural- an s is added to the end.

If the adjectives ends in a consonant, an es is added to the end to make that adjective plural.

Here are some more adjectives. Keep in mind that all the -o ending adjectives have a feminine equivalent that ends in -a.