Voted Best Answer
Aug 25, 2012 - 03:43 PM
(I'm a user of Fluenz, not an instructor.) It's called 'la d eufonica" because when d is added to a, e or o before a word beginning with a vowel it makes the phrase sound more pleasing when spoken. Compare "lei e io" and "lei ed io", the second is more pleasing to speak and hear. There are no hard and fast rules regarding its use, but more commonly used when the next word starts with the same vowel. Not mandatory to teach at this level as it's still correct not to add the d, but I'll guess it might appear in Levels 4 or 5.