Partly because of the popular omission of apostrophe-like characters, the four sounds represented in Hànyǔ Pīnyīn by j, q, zh, and ch often all become ch, including in many proper names. However, if the apostrophe-like characters are kept, the system reveals a symmetry that leaves no overlap: The non-retroflex ch (Pīnyīn j) and ch (Pīnyīn q) are always before either ü or i, but never ih. The retroflex ch (Pīnyīn zh) and ch (Pīnyīn ch) are always before ih, a, ê, e, o, or u.
Partly because of the popular omission of apostrophe-like characters, the four sounds represented in Hànyǔ Pīnyīn by j, q, zh, and ch often all become ch, including in many proper names. However, if the apostrophe-like characters are kept, the system reveals a symmetry that leaves no overlap: The non-retroflex ch (Pīnyīn j) and ch (Pīnyīn q) are always before either ü or i, but never ih. The retroflex ch (Pīnyīn zh) and ch (Pīnyīn ch) are always before ih, a ê, e, o, or u.