celyn,
how about you try this? pick a song that he likes (J reacts very well to music). so for eg, if it's "twinkle twinkle", sing the song with him and do some actions or better still, find a star to flash to him when u come to the word. then after awhile, ask him, "yu ze, what is this?" and point to the star. repeat the word "star" many times in your conversation with him.
i tried this with J and initially, when i said "star", he will point to places with star, e.g. singapore flag, star in his storybook, etc. after many days of me repeating star, he finally said the word.