You can't express your ideas fluently in English because the ideas in your brain are in Chinese. Imagine you can only play the piano. You h***e a lot of songs in your head, for example, Beat it by Michael Jackson. Suddenly I want you to play the song on the guitar. You h***e the song, you h***e the melody in your head but you can't play it on another instrument. You've learned this melody on the pi…。