• Basic forms
• 食べる — to eat / base form
• 食べます — polite / I eat / masu form
• 食べた — past / ate / ta form
• 食べて — te-form / eat (and…) / linking or request
• 食べない — negative / don’t eat / negative form
• 食べれば — if (I) eat / conditional
• 食べろ・食べよ — eat! / imperative
• Other common forms
• 食べたい — want to eat / 〜たい form
• 食べられる — can eat / be eaten / potential / passive
• 食べられた — was eaten / could eat (past)
• 食べられない — can’t eat / can’t be eaten
• More
• 食べよう — let’s eat / 〜よう form
• 食べなかった — didn’t eat / negative past
• 食べている — eating right now / progressive

食べる (たべる) is an ichidan (る-verb). Drop る and add endings like ます, た, て, ない. A very regular and essential verb — used for eating any kind of food.