"" These letters are vowels. The letter 'W' can be used either as a vowel (when it is said 'oo' like in the Welsh word 'cwm' (coom) meaning 'valley') or as a consonant (when it is said like it is in English, for example in the Welsh word 'gwyn' (gwin) meaning 'white'). This is the same with letter 'I' which can also be used as a consonant (when it is said like an English Y like in 'iogwrt' (yog-oort) meaning yoghurt. 