I can't speak for Malaysia, only Singapore.

Romanising Chinese names with 1 word corresponding to 1 Chinese character, in the dialect of the person in question, has been the norm in Singapore since English arrived on the scene in 1819, way before Hanyu Pinyin was invented. This was not just the norm in Singapore - the Indonesian Chinese founder of Gudang Garam, for example, was born Tjoa Ing Hwie and named his son Tjoa Too Hing.

Given Singapore’s majority southern Chinese population and the familiarity with Chinese naming conventions, there has been no confusion over whether the person in question has a middle name. There has never been a policy that says one word should correspond to one character, nor have there been any studies on the matter as far as I can tell. In Singapore’s context, it is simply logical for Chinese names to be rendered as such.

That aside, the names you mentioned have another interesting characteristic, which is that the surname is romanised dialect while the first name is in Hanyu Pinyin Mandarin. Thus, the question is not just, why is there a space, it is, why did Singapore Chinese naming conventions seemingly get stuck between the ‘old school style’ romanised dialect names with the space and the more recent Hanyu Pinyin Mandarin names without the space?

The first of such ‘half and half’ (or what a Singaporean might call ‘rojak’) names appeared in the 1980s. Before this, as mentioned, Chinese names were typically written on identity documents as romanised versions of whatever dialect the person’s family spoke, for example, Lau Mun Wai or the unfortunate Goh Lik Kok.

In 1979, however, the government launched the Speak Mandarin Campaign, with slogans that exhorted Singaporean Chinese to ‘Speak more Mandarin and less dialect’ and ‘No dialect, more Mandarin’. Dialects were cast as the ‘bad guy’, with Rabim Ishak, then Senior Minister of State, describing them as ‘vulgar, polluting, and associated with the uneducated’ while describing Mandarin as 'refined and part of the literary culture’ during a speech in 1980.

The drive to promote Mandarin over dialects extended to two very unpopular policies involving names. In 1980, it was announced that all government schools would register Chinese children with their Hanyu Pinyin names rather than the dialect names given at birth. Thus, a child who had been named Lim Boon Keng (romanised Hokkien with the space) by his parents would be registered and addressed as Lin Wenqing (Hanyu Pinyin without the space) in school.

At the same time, parents were strongly encouraged to register their newborns under their Hanyu Pinyin names instead of their dialect names. This met fierce opposition. In 1984, then Prime Minister Lee Kuan Yew laid out the rather lacklustre results in a speech.

When parents registered their children’s names, between August ‘82 and July ‘84, one-fifth registered only their dialect names, a total rejection.

i.e. 20% continued registering their children as LEONG MUN WAI or GOH CHOON SWEE.

Over one-third registered their dialect names, with full Pinyin in brackets, a concession to their identification with Chinese of different dialects, a tentative and reluctant acceptance.

For example, KOH SWEE LIN (XU RUILING).

Nearly one-quarter registered their surnames in dialect and their personal names in Pinyin, a partial acceptance.

For example, KOH KAI LING. 'Partial acceptance' may have been a touch pessimistic - it was common among this group to also have the full Hanyu Pinyin name in brackets e.g. KOH KAI LING (XU KAILING).

In other words, 80% of parents refused to render their child’s entire 'main' name in Hanyu Pinyin.

Even for the third category of parents, names continued to be rendered 'with the space' - no big surprise, since this was the norm. This has not been studied, as far as I know, but my personal opinion is that there were 3 reasons for this.

Firstly, few parents at the time would have had the chance to study Hanyu Pinyin, let alone its naming conventions.

Secondly, parents simply substituted Mandarin pronunciation for dialect pronunciation while keeping to the conventions they were familiar with.

Thirdly, the Hanyu Pinyin names in brackets would have been rendered by the clerk who would have been trained in the 'correct' way to write them i.e. ‘without the space’. There was thus no need to get the ‘main’ name ‘right’. This was unlike parents who rendered their child’s entire name in Hanyu Pinyin, as we will see later.

So what exactly was the problem with rendering the child’s entire name in Hanyu Pinyin? The issue was not Mandarin or Hanyu Pinyin per se - a third of parents had no objection to including a Hanyu Pinyin name and a quarter were happy to not have a dialect first name at all.

The main issue, in fact, was that a full Hanyu Pinyin name involved changing the surname. For example, a father whose ancestors were all Chias, and whose documents identified him as a Chia as well, would have been encouraged to make his son a Xie. That the Chinese characters remained the same did not help. A surname was an important, symbolic link to one’s forefathers and Chinese Singaporeans found the thought of changing it disrespectful. In one case, a man who actually did change his children’s surnames to the Hanyu Pinyin equivalent was told by a fortune teller that the spirits of their ancestors would be unable to recognise them as a member of the family, and would thus not be able to offer their protection. In other areas it could be argued that Mandarin could help unite the speakers of different dialects and allow communication with China and Taiwan. However, changing surnames brought none of those benefits, only costs.

At the time of Lee Kuan Yew’s speech, only 20% had gone the whole hog and registered their children, surnames and all, under Hanyu Pinyin names with correct naming convention. His grandson, for example, born in 1985, was named LI SHENGWU, with no additional name in brackets. Registering such a name as LI SHENG WU (LI SHENGWU) would have been quite redundant, in any case, telling the clerk that one wished to register a name in Hanyu Pinyin would have resulted in the clerk helping to ensure that it was done ‘right’.

The proportion of parents registering full Hanyu Pinyin names later fell to 12% in 1987, despite the government’s exhortations. In 1991, the government admitted defeat on this issue. Schools no longer forcibly registered children under their Hanyu Pinyin names, and parents were no longer encouraged to register their newborns using Hanyu Pinyin. Adding a Hanyu Pinyin name in brackets thus fell out of fashion.

However, dialect names did not make a full comeback, due to the overall success of the Speak Mandarin Campaign. Increasingly, to be Singaporean Chinese meant speaking Mandarin.

The number of households using Mandarin as the primary household language increased from 13% in 1980 to 30% in 1990. An entire generation of young people learned only the basics of their dialect or lost the use of it altogether - 64% of young people were using dialect in 1980, 7.2% in 1990 and just 2.5% in 1999.

Thus, giving a child a Mandarin first name became increasingly common. In some cases, parents might not even have been familiar enough with their dialect to come up with a dialect name. The group opting to register surnames in dialect and first names in Hanyu Pinyin thus grew throughout the 80s and continued to do so even after 1991. After the Hanyu Pinyin name in brackets fell out of fashion, the conventions of the 'main' name remained, resulting in names such as the ones you give in your question - Lee Jia Hui and Tan Xuan Ming.

All in all, it could be said that there is no real reason that Singaporean Chinese opted to preserve the 'space'. Rather, there was not enough of a motivation for them to do away with it, and so it just hung around.

An interesting final point is that, while there continues to be variety in Singaporean Chinese names, the ‘space’ is indeed very common. So common, in fact, that some China nationals who take up Singapore citizenship have opted to insert it in their names in their new identity documents, thus signalling their commitment to their new home. The space in the name has become an interesting little part of the Singaporean Chinese identity.

Ng P.C.L. (2017) A Study of Attitudes of Dialect Speakers Towards the Speak Mandarin Campaign in Singapore. Singapore: Springer Verlag Singapore.

Teo, T.S.H. & Lim, V.K.G. (2002) Language Planning and Social Transformation Strategies to Promote Speak Mandarin Campaign in Singapore. Singapore: School of Business, National University of Singapore.

Bokhorst-Heng, W. (1999) ‘Singapore’s Speak Mandarin Campaign: Language Ideological Debates and the Imagining of the Nation’, pp. 235-265 in J. Blommaert (ed.) Language Ideological Debates. Berlin; New York: Mouton de Gruyter.