Distinctive features of GR include the use of iu for the close front rounded vowel spelled ü or simply u in Pinyin.
A neutral (unstressed) tone can optionally be indicated by preceding it with a dot or full stop: for example perng.yeou "friend".
GR, like Pinyin, uses contrasting unvoiced/voiced pairs of consonants to represent aspirated and unaspirated sounds in Chinese.
Another feature of GR surviving in Pinyin is the representation of words (usually of two syllables) as units: e.g. Beeijing rather than the Wade-Giles Pei3-ching1.
This potential for confusion can be seen graphically in the table of initials, where the bold letters j, ch and sh cut across the highlighted division between alveolo-palatal and retroflex.
Pin'in, the GR spelling of the word "Pinyin", is itself a good example: the apostrophe shows that the compound is made up of pin + in rather than pi + nin.
Wherever possible GR indicates tones 2, 3 and 4 by respelling the basic T1 form of the syllable, replacing a vowel with another having a similar sound (i with y or e, for example).
In A Grammar of Spoken Chinese he introduced a subscript circle (˳) to indicate an optional neutral tone, as in bujy˳daw, "don't know" (Pinyin pronunciation bùzhīdào or bùzhīdao).
Note that T1 is the default tone: hence Shinjiang (Xīnjiāng), for example, is spelled using the basic form of both syllables.
GR does not reflect this change in the spelling: the word for "fruit" is written shoeiguoo, even though the pronunciation is shweiguoo.
[9] The commonest of these, followed by their Pinyin equivalents, are: In its original form GR used the two "spare" letters of the alphabet, v and x, to indicate reduplication.
This mimicked the method by which the Japanese writing system indicates repeated Kanji characters with an iteration mark (々).
[10] This concise but completely unphonetic, and hence unintuitive, device appears in Chao's Mandarin Primer and all W. Simon's texts (including his Chinese-English Dictionary).
Eventually, however, it was silently discarded even by its inventor: in Chao's Grammar as well as his Sayable Chinese all reduplicated syllables are written out in full in their GR transcription.