Depending upon the dialect, vowels might be matter to various mergers ahead of /l/, so that e.g. fill /ˈfileɪl/ and sense /ˈfiːl/ or pull /ˈpʊl/ and pool /ˈpuːl/ will not be distinguished. In Northern Ireland, Scotland and plenty of North American dialects the distinction concerning /ʊr/ as in courier plus https://collinogsax.tinyblogging.com/about-phim-trẻ-em-75915901