Because primary school students have never learned phonetic symbols, the only way to pronounce them is pinyin, so primary school students love to remember words as pinyin at the beginning of learning English.

I was like this when I was a kid. If you teach students phonetic symbols in grade three or four, don't teach them too early, because you are learning pinyin in grade one. If the first grade teaches pinyin and phonetic symbols at the same time, students will be confused. So the third and fourth grades are more suitable. After teaching phonetic symbols, students generally don't remember words with pinyin.