How to cure a zombie villager in Minecraft for cheap trades
One Golden Apple and one Splash Potion of Weakness turn a zombie villager back into a villager, and the villager rewards you with a permanent discount.

The Golden Apple is a food that heals and protects: it gives Regeneration and extra hearts of Absorption. It is also the key to curing zombie villagers.
It is made with the Crafting Table from 8 × Gold Ingot and Apple.
Eating one grants Regeneration II for 5 seconds and Absorption for 2 minutes, which adds golden hearts on top of your health. You can eat it even when you are not hungry, which makes it a classic emergency snack in fights.
To cure a Zombie Villager, throw a splash potion of Weakness at it, then feed it a Golden Apple; it turns back into a villager after a while and offers you discounts.
Craft it from eight Gold Ingots around an Apple. Horses, donkeys and mules also eat it, which helps tame and breed them. The Enchanted Golden Apple is much stronger but cannot be crafted.
8 × Gold Ingot + Apple → Golden Apple
// Slots with several items cycle through every accepted option.
One Golden Apple and one Splash Potion of Weakness turn a zombie villager back into a villager, and the villager rewards you with a permanent discount.
Golden Apples, a few Milk Buckets against the Wither effect, and food.
At the Crafting Table: 8 × Gold Ingot and 1 × Apple give 1 × Golden Apple. It can be found as loot in Igloo, Trial Chambers, Mineshaft, Woodland Mansion and 5 more.
It restores hunger and grants Regeneration and Absorption, and it cures zombie villagers weakened by a potion. Animals that eat it: Horse, Donkey and Mule.
4 hunger points (2 drumsticks) and 9.6 saturation. Effects: Regeneration (level II · 5 s) and Absorption (level I · 120 s).
A Balanced Diet (Eat everything that is edible, even if it's not good for you); Oh Shiny (Distract Piglins with gold).