Mandarin wasn't very commonly used for day to day conversation in Singapore during the 1960s. Regional dialects like Hokkien (Min Nan) were way more common, even amongst expatriates that spoke local languages.
Inspector Amran wears two bars of medal ribbons. There are duplicates of two ribbons - the ribbon with three white and two black bands and the one with three green and two black band. Each appears on both the upper and lower bars.