Singapore is a multicultural society that has four official languages, namely English, Mandarin, Malay and Tamil, of which English is the official working language and Malay as a national language.
Singapore's first encounter with the English language can be traced back as early as 1819 when the founding father of modern Singapore, Sir Stamford Raffles, started taking Singapore under its wing.
The population that had already settled there were Malay settlers. Once the port had been established, Singapore attracted traders from various countries, and settlers from China and India arrived in Singapore and created the multicultural society that it is today.
After Singapore gained its independence, the government decreed Malay as Singapore's national language for symbolic and historic reasons. Although the national anthem, 'Majulah Singapura' is in Malay, only the Malay population of Singapore are fluent in this language.
While Mandarin and Tamil are nationally recognised and spoken in and among one's own distinct ethnic groups, English remains the lingua franca as well as the official business language of Singapore.
Unofficially though, and perhaps more commonly, you'll hear the locals speak with a pidgin language that defies understanding to untrained ears. Singlish is a English-based creole language which comprises of an amalgamation of Mandarin, Malay and other Chinese dialects.