The pronunciation of the titles lieutenant and colonel, given to selected army and police officers, respectively, is both challenging and interesting.
First, the British and American pronunciations are very different in the case of lieutenant. In British English, the pronunciation is [lefˈtenənt], see and listen here, whereas in American English it is [luːˈtenənt]. Second, colonel is pronounced as [ˈkɜːnl] in British English but as [ˈkɜːrnl] in American English, see and listen here. Neither of these pronunciations is obvious from the spelling. Instead, colonel is pronounced exactly like the word kernel. Curiously, in French, colonel is pronounced just at it is spelled. You may also notice that dubbing artists sometimes mispronounce colonel (namely, pronounce it just like its spelled) when translating movie dialogue from English to German.