Sometimes it's tough to tell a manager face to face because, as Kroger managers, there is a good chance that they will act like a total ****head about you giving your notice. I would leave a letter on a manager's desk and then ask later, "Oh hey so and so, did you see my letter?" Then the ball is in their court to mention that it was a resignation notice. That's what I've done in the past, anyway.
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You had an employee bbq yesterday? Thanks for telling the night crew...