According to Yu Bor-chuan, chief architect of Tongyong Pinyin, his system is basically just a modified version of Hanyu Pinyin, with such defects as "x" and "q" removed. Says Yu, "The systems only differ by 15 %. Once you've learned Tongyong Pinyin, you pretty much know Hanyu Pinyin."
而研發「通用拼音」的中央研究院民族學研究所行為組助研究員余伯泉表示，其實通用拼音是間接使用漢語拼音，對其稍作修正，改善了漢語拼音 x、q 的若干缺點，「與漢語拼音只有百分之十五的差異，學會通用，就幾乎學會了漢語。」