Did Adam ever become a Warlock? Sam and Darwood son.

In the original series, I don't believe Adam ever began showing signs of witchcraft. In the "Tabitha" follow-up series, Adam was clearly a mortal (although in the original 1976 "Tabitha" pilot, Adam was clearly a warlock).

Yes, in the episode Adam, Warlock or Washout, Adam shows that he has powers when the Witches Coven comes to the house to test him. At first Maurce tries to help him, but then Adam does it on his own and levitates things, pops Darrin into the house from his golf game, pops Samantha into the kitchen, pops himsef in and out oif the living room and at the end pops himslef a glass of milk because he's thirsty.