hardly / scarcely / barely
The double negative with these three adverbs.
Hardly, scarcely, and barely are negative adverbs, so pairing one with not or without doubles the negation. Write could hardly, never couldn’t hardly, and with hardly any, never without hardly any.
Examples
Use The witness could hardly recall the license plate.
Use The crew finished the roof with hardly any help.
Avoid The witness couldn’t hardly recall the license plate. (Change couldn’t to could.)
Avoid The crew finished the roof without hardly any help. (Change without to with.)