A or an?

La maestra di mia figlia (V elementare), a proposito degli articoli indeterminativi, insegna che si dice a English man (perché man inizia con consonante).

Io ho sempre saputo che l’articolo segue l’aggettivo o la parola che ha davanti, dunque an English man, a story, an apple, an old man, a young man. Si mette an se c’è prima la vocale, a se c’è consonante. Ho ragione?

We sincerely hope that your daughter’s teacher isn’t truly telling her that she should say “a Englishman” (which is one word and not two, by the way)! It is “an Englishman” and the word “man” is irrelevant. All the other examples you give are correct: a story (consonant), an apple (vowel,) an old man, a young man. These other examples may help: an Italian, a Romanian, an Italian man, a Romanian man, a beautiful dog, an ugly dog, an intelligent man, an intelligent woman, a stupid man, a stupid woman.