Learn Romanian: Voiam să vă explic rugămintea mea. - I wanted to explain my request to you.

Using the imperfect voiam softens the statement. Just like saying 'I wanted to' in English, it acts as pragmatic mitigation to make your intention sound more polite and less demanding than the blunt present tense vreau (I want). It is a very common alternative to the conditional aș vrea.

Are we using vă as a direct or indirect object in this sentence?

It is an indirect object (dative case). The verb a explica requires you to explain something (the direct object, here rugămintea) to someone (the indirect object, here vă). So vă translates to 'to you' (formal or plural).

Why is the noun rugămintea used with a definite article if the English translation is just 'my request'?

In Romanian, possessive adjectives like mea almost always require the noun they modify to take a definite article. The base feminine noun is rugăminte (request), which must become rugămintea (the request) before you can add mea (my).

I sometimes hear people say vream instead of voiam. Are they interchangeable?