The Republic of China has used Wade-Giles for decades as the de facto standard, co-existing with several official but obscure Romanizations in succession, namely, Gwoyeu Romatzyh (1928), MPS II (1986), and Tongyong Pinyin (2000). Taiwanese placenames in international use have still been virtually all in Wade-Giles. Many Taiwanese Americans and Taiwanese Canadians also have their Chinese names written in Wade-Giles, while consistently ignoring some punctuation.
The Hanyu Pinyin system is more widely used and is the official system of the People's Republic of China. However, international references to Taiwanese people and places are still in Wade-Giles mostly.
On the other hand, people unfamiliar with the Wade-Giles often ignore the apostrophes, even so far as leaving them out when copying texts, unaware that they represented vital information. Hanyu Pinyin addresses this issue by employing the Latin letters customarily used for voiced stops, unneeded in Mandarin, to represent the unaspirated stops: b, p, d, t, g, k, zh/j, ch/q.
Partly because of the popular omission of the apostrophe, the four sounds represented in Hanyu Pinyin by j, q, zh, and ch all become ch in many literature and personal names. However, were the diacritics to be kept, the system reveals a symmetry that leaves no overlap:
The non-retroflexch (Pinyin j) and ch' (Pinyin q) are always before either i or ü.
The retroflexch (Pinyin zh) and ch' (Pinyin ch) are always before a, e, ih, o, or u.
-ih after the retroflexch, ch', sh, and j (Pinyin zh, ch, sh, and r).
These empty rimes are all written as -i in Hanyu Pinyin (hence undistinguishable from true i as in li), and all written as -ih in Tongyong Pinyin. Zhuyin, as a non-Romanization, does not require the representtaion of any empty rime.
What is pronounced as a close-mid back unrounded vowel is written usually as -e as in pinyin, but sometimes as -o. This vowel in an isolate syllable is written as o or ê. When placed in a syllable, it is e; except when preceded by k, k', and h, when it is o.
What is actually pronounced as -uo is virtually always written as -o in Wade-Giles, except shuo and the three syllables of kuo, k'uo, and huo, which already have the counterparts of ko, k'o, and ho that represent pinyin ge, ke, and he.
In addition to the apostrophess used for distinguishing the multiple sounds of a single Latin symbol, Wade-Giles uses hyphens to separate all syllables within a word, whereas Pinyin only uses apostrophes to separate ambiguous syllables. Originally in his dictionary, Giles used left apostrophes (‘) consistently. Such orientation was followed in Sinological works until the 1950s or 60s, when it started to be gradually replaced by right apostrophes (’) in academic literature. On-line publications almost always use the plain apostrophe ('). Apostrophes are completely ignored in Taiwanese passports, hence their total absence in overseas Chinese's names.
If the syllable is not the first in a word, its first letter is not capitalized, even if it is a proper noun. The use of apostrophes, hyphens, and capitalization is frequently not observed in placenames and personal names. For example, the majority of overseas Chinese of Taiwanese origin write their given names like "Tai Lun" or "Tai-Lun", whereas the Wade-Giles actually writes "Tai-lun". The capitalization issue arises partly because ROC passports indiscriminately capitalize all letters of the holder's names (beside the photograph). It is also due to the misunderstanding that the second syllable is a middle name. (See also Chinese name)
Wade-Giles uses superscript numbers to indicate tone, and official Pinyin uses diacritics. The tone marks are ignored except in textbooks.
Wade-Giles chose the French-like j to represent a Northerner's pronunciation of what now is represented as r in Pinyin.
Ü (as in 玉 "jade") always has umlaut above, while Pinyin only employs the umlaut only in the four cases of lü, lüe, nü, and nüe.
The Pinyin vowel cluster ong is ung in Wade-Giles. (See Confucius as an example.)
After a consonant, the Wade-Giles vowel cluster uei is written ui in pinyin. However, both Romanizations, unlike some others, use iu and un instead of the complete syllables: iou and uen.
I is never preceded by y, as in pinyin. The only exception is in placenames, which are hyphenless, so without a y, syllable ambiguity could arise.
The isolated syllable eh! is written as ê, like in Pinyin. (Schwa is occasionally written as ê as well.) But unlike Pinyin, which uses -e if there's consonant preceding the sound, Wade-Giles uses -eh. (See circumflex)
In addition to being the schwa, ê also represents the Pinyin er as êrh.
