Grapheme –ow

It has two pronunciations:

[ au ]      clown, now, town, down, gown, frow, brown, bow, brow, row, sow, fowl, cow

[ ɔu ]     bow, blow, bowl, borrow, grow, know, fellow, furrow, low, marrow, mow, narrow, pillow, show, rainbow, throw, willow, wheelbarrow, yellow, sow, sorrow, scarecrow, sparrow.

[ ɔu ] USA,

[ əu ] UK