Long, long ago and far, far away, I once learned that
w is really more often a part of a diphthong rather than a pure vowel. Ho
w, co
w, fe
w. Examples of when it is a consonant
way,
wizard. The best way to tell is if it creates a separate syllable (consonant), or divides syllables. If not, it is a "vowel' forming a diphthong. There have been other discussions about this on these forums, but they are highly argumentative and often not very consistent. Take a look at them if you'd like.
Likewise with y: boy diphthong; yes consonant. Kennedy (definitely a vowel).