How to use "underhand"and"underhanded"
“People are complicated creatures; on the one hand able to perform great acts of charity; on the other，capable of the most underhanded forms of betrayal. ”
"underhand"and"underhanded" are all adjective, can you tell me the difference between them?

Question

How to use "underhand"and"underhanded"
“People are complicated creatures; on the one hand able to perform great  acts of charity; on the other，capable of the most underhanded forms of betrayal. ”
 "underhand"and"underhanded" are all adjective, can you tell me the difference between them?

Answer

"underhanded" means deceitful or acting in a dishonest way - "I thought I was buying a good car but that underhanded salesman cheated me with a bad engine"

"underhand" is a method of holding or throwing something where the hand is under the object  - "The woman threw the ball to me underhand, very gently and slowly" (when the ball left her hand, her hand was under it)

Answer

I believe you also need to check with some Americans, certainly I've been told that "underhand" means "it is being dealt with" so like "under control" by Americans.

Ideas anyone?