If you can read Pinyin (PY) you can already read the basic (Tone 1) form of most GR syllables. Many syllables are in fact written identically in both systems (eg Lai, Ping, Bie, Dou, Gu).
But there are three crucial differences: learn them and you will be well on the way to reading GR fluently; ignore them and your reading will be remain at best a hit-or-miss affair. These essential differences are:
There are one or two other peculiarities about GR, but they should not prove much of a problem: eg Ts- and Tz- are used where PY uses C- and Z- respectively. Note that final -l is used where PY has -r : this is because GR uses -r to indicate Tone 2.
- -y as the only vowel is always an "apical" allophone of [i], as in PY Si, Chi and Ri; while -i (with or without other vowels) is always the plain vowel, as in PY Bi and Qi.
- Ch/Sh/J when followed by -i- correspond to the palatal consonants (PY Q/X/J); otherwise they represent the retroflex consonants (PY Ch/Sh/Zh). This can be quite confusing at first, because some syllables are identical in both systems: eg Chu, Shu, Ji. But GR has Ching, Shing, Ju where PY has Qing, Xing, Zhu.
- -iu represents the rounded front vowel (PY qu, nü [u-umlaut]); -iou is used for the diphthong spelt -iu in PY (eg Qiu, Liu).
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