Most of the time w is used as a vowel.  They didn’t teach me this in school; I’m not sure it’s being taught in school even now.  Consider the following:

Fawn / faun:  aw has exactly the same sound as au.  Can you think of any words in which aw is not a vowel sound?

Blew / blue:  ew has exactly the same sound as ue.  I can’t think of many words in which ew does not have this sound.  Ewe (pronounced you) would be one exception.

Flow / floe: same thing, ow in this and many other words has the same sound as oe, or oa.

Town / mound: in another group of  words ow has the same sound as ou.

In all of these instances, w functions as a vowel.  But what about when w is used at the beginning of a word?

In French, the w sound at the beginning of a word is represented by ou, as in ouest, the French form of west, pronounced the same way.  W is not found in any native French words, but is used in words imported from other languages.  This w or ou sound at the beginning of a word is called a semi-consonant in French.  In English it is called a semi-vowel.

In some cases the w at the beginning of words imported into French  is sounded like a w in English, in other words it is given a v sound.  Wagon is the word used in French for a rail car and is pronounced vagon.

You see, in English we call W a double-u and use it as a vowel or semi-vowel.  In French it is called a double-v and is considered to be a consonant or a semi-consonant.

One of the first things I was taught in school was that the vowels are a e i o u and sometimes y.  This is correct, as far as it goes.  Why didn’t they tell me that w is used as a vowel as least as often as y?

Why didn’t I figure it out for myself before I got into my sixties?