E and Ed
Salve a tutti!
I understand that ‘ed’ is used before vowels, but sometimes I see ‘e’ before vowels and apparently ‘ed’ is incorrect?!
Grazie e buonanotte!
That is the so-called euphonic D and it serves only to create a good sound, since it avoids the repetition of two equal vowels, it's present in ed/ad/od but the last one is less common than the others. E.g.
It's a very debated topic, ther are many opinions, for example you may find both famous writers who use D with different vowels (e.g.Pirandello, Pascoli, Verga) and famous writers who don't use it even if there are two equal vowels (e.g.D'Annunzio, Manzoni,Leopardi).
Anyways, currently, as mmseiple said, it seems to prevail the thesis according to which it's better to use the D only when there are equal vowels (instead in the past it was more used, with different vowels too).
However, we have exceptions in which the use is recommended although there are different vowels, because in this way the sound seems "more elegant", e.g.
tu / lui / lei ed io, ed io, ad esempio, ad eccezione, fino ad ora, dare ad intendere, ad opera di, varie ed eventuali, ad ogni istante, ad ogni modo ect
Instead some cases in which D is always discouraged are:
when, although there are two equal vowels, it's totally reproduced the same sound, e.g. Ed editori, Ad Adamo, Od Odisseo
when there are commas, in Italian "inciso", e.g.e, ogni volta che lui arriva , chiede sempre di te
before aspirated H, such as with foreign words, e.g. e hamburger.
Ed before an E is generally recommended, but not necessary.
Ed before other vowels is generally not considered incorrect, but some now discourage it.
A lot of it depends on who you talk to. From my Italian studies, it seems like the prevailing advice now is to use the D only when the word is followed by the same vowel ("ed" before E, "ad" before A), but some will tell you not to use it even in those situations.