After days of practicing, my 18 months old toddler finally mastered her wooden alphabet puzzle. She worked hard for it. Her first few tries of doing the alphabet puzzle was not too easy. There were times she got frustrated because she can't put a letter right into the space where it should go. When she gets frustrated, she either handed the letter to us (so we can put it for her) or throws it on her side. But even if she had these bouts of frustration during her practice sessions, she still continued to hone her ability to do it correctly. In the end, her determination to learn and master her ABC puzzle paid off. Before, the puzzle looked challenging to her; now, it's too easy. She already knows where each one goes and how to position every letter correctly. It didn't take that long for her to learn and master the alphabet puzzle. Probably a week and few days. There's a saying that "practice makes perfect." This is so true with her and her wooden puzzles.
Currently, I am teaching her what picture is in each letter and ask her to point to the picture that I'm asking her to identify. She already knows some of it and still working on some pieces.