hard and hardly

1. Hard can be an adjective or an adverb

• It's a hard job (adjective)


• This is very hard bread (adjective)


• You have to word hard. (adverb)
  (not You have to work hardly)


• Hit it hard. (adverb)

2. Hardly in an adverb. It means 'almost no' or 'almost not'

• He hardly works at all (= He does very little work)


• I've got hardly any money.


• He knows hardly anything about geography.

Note that hardly, hardly any, hardly ever etc are much more common than almost not, almost no, almost never etc