Lingering over lingerie?

Rambling through the quagmire that is English spelling and pronunciation.

I PUT up the catchy title not to discuss women’s undergarments and nightclothes – no, I don’t have that sort of fetish – but to draw the reader’s attention to the fact that the words lingering and lingerie are not pronounced as they are spelt. For that matter, why are the words linger, lingerie, and singer, which contain the same letter-cluster “nger”, pronounced differently?