Guess should not be used in the sense of think or imagine.
Handy should never be used to express nearness.
Hanged should be used to express the execution of a human being. Hung is the past participle in all other uses.
Hardly. "I can hardly see it," not "I can't hardly see it."
Healthy which means "possessed of health" should be distinguished from healthful and wholesome which mean "health giving."
High should not be confused with tall.
Home is not a synonym for house. A beautiful house is a very different thing from a beautiful home.
Honorable as a title should always be preceded by the.
How should not be used for what, or for that. It means "in what manner."
How that should not be used when either one will do alone. Such a sentence as "We have already noted how that Tillotson defied rubrical order...." is very bad.