The “da” of course is a contraction of “de” and “a”, which means in the first case the “a” has been omitted. My impression is that it is far more common to use “a minha” but there are apparently exceptions. What are the rules regarding this? I assume they would apply to “o meu” as well.
I just came across a similar phrase in my current lesson:
Estou em frente à tua casa.
The “à” here is of course a contraction for “a a”. This is essentially another example of what I’m about in my original post. Is this version also okay:
Estou em frente a tua casa.
I’ve changed “à” to “a” in this alternative, making the phrase use “tua” instead of “a tua”.
@pwsteele, the noun “casa” is a bit of a special case, where it’s often acceptable to add or omit the definite article at will without affecting the meaning. So, you can say both “perto de” or “perto da”, just like you can say “em minha casa” or “na minha casa”. “Em frente a” is also acceptable, but you’ll mostly see “em frente à”.
Otherwise, generally speaking, definite articles before possessives change the feel of a sentence. For example, in A mochila é tua vs A mochila é a tua, there’s a difference in where the focus lies:
When you add the definite article ‘a’, you put more emphasis on the fact that that particular backpack is theirs, as opposed to other backpacks.
When you just say A mochila é tua, you’re more neutrally describing the possessive relationship between the backpack and its owner.
I’ve struggled with this before and reading this explanation through several times I still don’t get it (I understand the special case of “casa”. I’m referring to the more general examples).
I suspect that this is because this is a distinction that English doesn’t much trouble itself with. For example:
that backpack is his
the backpack is his
that’s his backpack
the backpack over there is his
his backpack is that one
all mean the same thing. I think I can only create the kind of distinction that you are making (on the assumption that I’ve understood you) by adding the word “only”.
only that backpack is his
but I suspect that is an even stronger statement of the relationship.