CHILD
It was childish behavior (behavior). having immature behavior, negative
It was childlike behavior. qualities like a child, positive
CONFIDE
We are confident about winning. Sure [L.confidere]
The message is confidential. Private [L. confident]
CRISP
It is a crisp day, today. Cool and dry
It is a crispy cracker. Thin and crunchy (makes a pleasant sound )
FUN
We had a fun time at the movies. Amusing
We saw a funny movie. causing laughter
TACT
The general made a tactical advance. military move [L. tacticus]
He is a tactful politician. Having skills handling situations [L. tactus] tact (n.) – skill in dealing with difficult or delicate situations
TASTE
Your food is tasty. Having a good taste
You are a tasteful dresser. Having good judgment for fashion
WORTH
He is a worthy competitor.
He is a worthless competitor.