Original sentence: The first reaction step is nucleophilic addition of the base (for instance the hydroxy anion) to the carbonyl carbon of the aldehyde.This hydride transfer simultaneously generates a hydroxyl anion and a carboxylate
Edited sentence: The first reaction step is nucleophilic addition of the base (for instance the hydroxide anion) to the carbonyl carbon of the aldehyde.This hydride transfer simultaneously generates an alkoxide anion (RCH22O-)and a carboxylic acid, which is rapidly deprotonated to form the carboxylate