Regarding where to draw the boundary, are R, W, and Y really vowels? The biggest difference I've noticed between vowels and consonants is that vowels don't involve touching parts of your mouth together. This makes it a lot easier to transition between letters. The second thing is that vowels are always voiced. H is otherwise a vowel, but it seems like it might be worth calling a consonant on that basis.

R at least is always considered a consonant, but the sound W makes is considered a vowel if it's a hard U or an OO, and the sound Y makes is considered a vowel if it's a hard E or the second half of a hard I (which seems to be a soft O followed by a hard E). Also, Y is often stated as being sometimes a vowel, even though it seems to always be a hard E.

W and Y are generally placed like a consonant would be, but this doesn't seem like it means much, since vowels can be placed anywhere. Consonants can't be placed three in a row. (Unless the first two have the same place, the first is not a stop, and the second is, like "mp" or "nt", which makes it particularly easy to pronounce. This leads to things like the Japanese word senpai being consistently mispronounced by Japanese speakers as "sempai", even though the only consonant Japanese syllables can end with is an N.) It looks like W and Y have this rule, but it's not so much that Y is never between two consonants as it is that if a hard E is between two consonants, it's not represented with a Y. And this still doesn't excuse R, which is frequently the only vowel between two consonants. For example, "bird", "herd", and "turd" are all written with different "vowels" next to the R, but they are all pronounced with just the R sound.

This always bugged me a lot. Am I the only one that sees this?