Sometimes the letter d is omitted in colloquial Spanish
In colloquial spoken Spanish the letter D is sometimes omitted in conversation.
The letter -d- is often not pronounced when it is located between two vowels, which is the case of most past participles as they usually end in -ado [pronounc: ao] and -ido [pronounc: ío]. This pronunciation is common in many areas in Spain and Latin America. For example:
Some nouns and adjectives
The -d- between two vowels at the end of the word of some nouns is also sometimes not pronounced.
Some words that end in -d
It is also very common to omit the -d when it is at the end of a word. For example:
In Madrid and the very central areas of Spain, in these cases, they tend to pronounce that final -d as a -z. For example:
It is important to remember that this aspect of colloquiallism/accent in Spain and Latin America is accepted in spoken Spanish, although the R.A.E. (Royal Spanish Academy) does not recommend it, in particular when participles are pronounced -ío.
In all cases, omitting the letter D is not acceptable in written Spanish, only in conversation.