I agree and was merely oversimplifying so the point would not be lost. Still I maintain that there is a qualitative difference between the use of pitch in Chinese and English, which creates a difficulty for a speaker of one language in learning the other. We can say: "He's here." and "He's here?" and make the difference between a declarative and interrogative sentence obvious through the modulation of pitch. You can't do that with Ta zai jer. You can't put a rising or falling tone on a single Chinese syllable that doesn't have it, or you change it into a different morpheme and lose the meaning. Yes, I know they do that in pop songs, but they restrict themselves to short sentences and a very small vocabulary that slavishly follows the context, thereby reducing ambiguity. I can almost understand Chinese pop lyrics.