The usual pronunciation of vase, in this country, is as a rhyme with mars. In the United States, it is more common for vase to rhyme with lace. Growing up on an Essex council estate with a Belgian mother whose native tongue was Flemish, however, I learned to rhyme vase with jaws.
This was but one example of my mother’s idiosyncratic English. She spoke of the old films we loved to watch as being “in white and black”, and regularly deployed a sort of guttural expostulation my sister still refers to as “the Flemish sound”. This was used to express a vast swathe of emotions, from surprise to incredulity to contempt to disgust to … well, pretty much any response.
The word chasm is one that we probably encounter more in written than spoken English. My mother pronounced it with a soft ch, as in chase or chicken. So I did too, on the rare occasions I said it aloud. I only learned the correct, hard c pronunciation in my late teens, when I was reading a passage aloud in an English class at school and my teacher raised an amused eyebrow. He gently corrected me when I finished reading.
Many years have passed, but I still find myself drawn inexorably to the pronunciations I learned at my mother’s knee. And, intriguingly, my sister finds herself increasingly using “the Flemish sound” as she grows older.