Hi, sorry I don't know how to write Chinese. Would like to share my experience.
My boys (at 4) likes to sing the song "Ding Dong" but don't know the exactly wording so I just write all the words, each on a half A4 paper to tell him each word. Very soon, he can rearrange all the word papers of the whole "Ding Dong" song in order and recognise all the words (he just treats it as puzzles game). In the past few months, he like "Da Cheong Kam", so I do the same, and now he can recognise all the words of "Da Cheong Kam" song. Cheers.