a as English a in father
e[1]   "     a "  fate[2]
i      "     i "  magazine
o[1]   "     o "  note[2]
u      "     u "  rule

These five sounds never vary, except that they are a little longer
when they are stressed and shorter when they are not, as Yo amo (I
love),[3] Amigo (friend), El cielo (heaven), Celeste (heavenly), Un
recibo (a receipt), Interés (interest), Yo como (I eat), Contar (to
count), Un buque (a ship), Una butaca (an armchair).

Y is considered a vowel in the conjunction y (and), and at the end
of a word, as Rey (king), Hoy (to-day).

[Footnote 1: E and o are sounded a little more open when they form
a diphthong with i and when they precede r followed by a consonant
or r or l final, as Fernando (Ferdinand), Un tercio (a third), El
tercer año (the third year), Porfiar (to insist), Amor (love), Español
(Spanish).]

[Footnote 2: The a and o of "fate" and "note" are not pure vowel
sounds. In English the a is distinctly pronounced a-ee and o is
pronounced o-oo.

In Spanish the first part only of the two sounds is permissible.]

[Footnote 3: The examples given with their English equivalents should be
learnt.