The little boy held his father's hand hardly; he didn't want to lose him

Explanation

The corrected version would be:"The little boy held his father's hand tightly; he didn't want to lose him."This is the error. The word hardly means only just; almost not; barely. The intended meaning is that the boy held his father's hand tightly, because he didn't want to lose him, not that he barely held it. The correct adverb to use in this context is "tightly."So, the corrected sentence is: "The little boy held his father's hand tightly; he didn't want to lose him."