When to use Boit vs. Bois. Also un and une. Thanks
You use "bois" when saying "I drink" or "You (informal) drink." Therefore "Je bois et tu bois." But "boit" is only for third person singular: He/She/It drinks: "Il/elle/on boit.
We have random spelling changes in conjugations in English too. We say "I speak" but "he speaks." It's the same concept here.