In English, you add a "s" or "es" to the end of regular verbs in the third person singular of the simple present (http://www.scientificpsychic.com/grammar/regular.html). So, you say "she drinks", "she studies", "she catches" instead of "she drink", "she study", "she catch".
In English, usually verbs only get an -s at 3rd person singular. In French, verbs change endings nearly with each subject. For your information, here are the conjugations of verbs "boire" and "manger":
- je bois, tu bois, il/elle/on boit, nous buvons, vous buvez (polite singular and plural), ils/elles boivent
- je mange, tu manges, il/elle/on mange, nous mangeons, vous mangez (same), ils/elles mangent.