Why I switched to bopomofo
The first year or so, I stuck to pinyin for learning about Chinese pronunciation. I made some progress, but when I moved back to the USA, I found another, local native speaking Chinese tutor. When she often lapsed into using the bopomofo phonetic representation that she had learned in grade school in Taiwan, I noticed it seemed to flip a switch in my brain. Using the bopomofo kept my brain in Chinese-mode and made me more aware of the distinct Chinese pronunciation of the sounds represented.
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A Simple BoPoMoFo Chart Helps Me Learn Chinese