It’s not so much whether the word is spelled with a vowel, but whether it makes a vowel sound.
In English, the y sound is considered a consonant when at the beginning of a word but a vowel elsewhere.
Europe makes a similar y initial sound as, e.g., yurt, young, yellow, yell, youth, etc. so in those cases the words take the “a” article instead of “an”.
A yurt, a youth, a yell, etc.
Likewise Euclidian, European, Uranus, ewe, user, universe, universal, all take the “a” article instead of “an”.
And in the reverse, words like hour and heir become “an hour” and “an heir” because the initial sound is a vowel even though the first letter is a consonant.
It’s not so much whether the word is spelled with a vowel, but whether it makes a vowel sound.
In English, the y sound is considered a consonant when at the beginning of a word but a vowel elsewhere.
Europe makes a similar y initial sound as, e.g., yurt, young, yellow, yell, youth, etc. so in those cases the words take the “a” article instead of “an”.
A yurt, a youth, a yell, etc.
Likewise Euclidian, European, Uranus, ewe, user, universe, universal, all take the “a” article instead of “an”.
And in the reverse, words like hour and heir become “an hour” and “an heir” because the initial sound is a vowel even though the first letter is a consonant.