The combination “ough” can be pronounced in at least eight different ways. The following sentence contains them: “A rough-coated, dough-faced, thoughtful ploughman strode the streets of the borough; after falling into a slough, he started to cough and hiccough.”
Thoughtful [thawt-fuh l]
Borough [bur-oh, buhr-oh]
Cough [kawf, kof]
Don’t even get me started on the British pronunciation of “Slough”.