Sandwiched between beautiful buildings

I took this photo in Malmö, Sweden. I walked along the street sandwiched between beautiful buildings. Come to think of it, one of my British acquaintances always mixes up with my pronunciations such as WORK v. WALK. He said WORK has exactly the same sound as BIRD, and WALK sounds exactly the same as HORSE. With that, I asked my American acquaintance how to pronounce WORK and WALK. He said WORK has exactly the same sound as BIRD, but WALK has kinda same sound as CHALK, but it more sounds like WOK as in super-popular Chinese restaurant. Is that true? It beats me. Always. I'm not a native English speaker and pronunciation has never been my forte.