You mean "d'fhan" ? (waited)
Yes, the d that is put before initial vowels of the verbs in the past, conditional and past habitual comes from the particle "do". And this is the same "do" that lenites the initial consonant of the verbs in the same tenses, except the do itself is not pronounced but the lenition remains.
There are dialects (in Munster) where all these do's may be still pronounced: do chuaigh sé, he went, and so on.
quote:There seems to be a complex set of pronunciation rules which is Tense dependent. i.e if its Autonomos the F gets sounded if not it becomes an H sound, and dh is sometimes ch and sometimes not. Is there a way to figure out what do sound when ??
Can you please give examples, because I'm not sure I understand what you mean in these questions...