Mandarin is the main language of communication between the different Chinese dialect groups in Malaysia. It is based on Standard Mandarin, the dialect native to speakers in Beijing, China. Mandarin dialects are spoken in northern and southwestern China, but the Standard Mandarin is adopted as the official spoken language of the People's Republic of China, called Putonghua; the official language of the Republic of China, called Guoyu; and one of the four official languages of Singapore, called Huayu. It is the language of instruction in Chinese-medium primary schools in Malaysia.
It may be surprising for some to learn, but the speaking of Mandarin never caught on in Malaya until the beginning of the 20th century. Most of the Chinese people in the country trace their ancestry to immigrants who arrived from southern Chinese provinces where Hokkien, Cantonese, Hakka, Teochew, Hainanese and other dialects were spoken. Contrary to popular belief, during the Ming and Qing Dynasty, few people outside the Beijing region spoke Mandarin. Despite the propaganda about Mandarin being the official language of the Chinese people, it was in fact the dialects that dominated the speech of the Chinese people in the provinces. It should also be pointed out that the majority of the provincial population comprised illiterate peasants, and only the scholars and government officials that have to deal with Beijing learned and spoke Mandarin. It was for this particular reason that the language got its English name, a corruption of the Malay word "mantri" (or in modern Malay, "menteri"), meaning the language of the ministers or bureaucrats.
Upon arriving in Malaya in the 19th century, many of these early Chinese immigrants were unable to communicate with those of a different dialect group from themselves, as there was yet no common language. Many picked up Malay along the way, and as a result, were forced to communicate with each other in that language rather than in Mandarin. The use of Malay as the common language caused several common Malay words to creep into the dialect of the early Chinese in Malay, particularly into Hokkien, examples being "jari" (finger), "batu" (stone) and "mata" (police, literally "eye").
It was only in the 20th century, with the fall of the Qing Dynasty, that there was a concerted effort to promote Mandarin as the lingua franca of the Chinese people, in China as well as in Malaya. Early Chinese schools in Malaya originally taught in the mother tongue such as Hokkien or Cantonese, switching only to Mandarin in the first quarter of the 20th century. It may sound radical today, but it took proactive movements such as Hu Yew Seah to actively promote the use of Mandarin in Malaya which resulted in the language being accepted as the common language for Chinese in general.
The Mandarin spoken in Malaysia (as well as in Singapore) is often of very different tone from that in Beijing. As in the case of English, it is localised. When encountering a Malaysian street name, for example, Jalan Bukit Kepong, the local Mandarin speaker will pronounce it "Jalan Bukit Kepong", despite it being translated phonetically as re-lan wu-ji jia-tong. There is less likelihood of creating confusion by using the common, Bahasa Malaysia name, rather than attempting to say it in a Mandarin name that nobody locally will recognise.