I agree with the distinction that's been made between learning as a
native language (or perhaps learning any language when one is very
young) and learning a second or subsequent languages.

        My son is 2 1/2, growing up in Israel, with English from me and Hebrew
from his mother. His Hebrew is dominant (we have a 50-50 joint parenting
agreement, but of course he gets Hebrew at kindergarten, and from about
70% of the friends/family to whom he's exposed).

        Anyway, what fascinates me - and I know I'm not saying anything new -
is to see how much he obeys the laws of each language.  Steven Pinker,
in his book The Language Instinct, quotes a list of possible grammatical
mistakes in English you might expect children to make, yet which are
hardly ever found. And indeed it amazes me how quickly he has absorbed
grammatical laws.

        Of course, Omri (that's his name) makes mistakes in both languages. In
English he sometimes says "mouses", and he tends to use "not" to negate
entire sentences (I say to him "that cat is very big, isn't she" and he
says "not that cat is very big").  In Hebrew he makes analogous
mouses-type mistakes (and, if Steg is reading this, he has the cutest
way of declining prepositions; e.g. he'll say "ani rotse lehavi kisei
velashevet alo" instead of "alav", and many similar constructions that
sometimes sound like some remnant of pre-Biblical Hebrew).

        Anyway, the bottom line is it seems to me that Omri has had from the
earliest stage a clear awareness that here are two languages, with
different rules, but he seems to soak up both with equal pleasure and
ease (again, allowing for the dominance of Hebrew in his outside world).

        And I'm sorry, but I can't resist ending with my strong impression that
if Omri could understand the question "Which is superior, English or
Hebrew?" he would look at me blankly for a minute before laughing me out
of the living room.

        Conlanglikeg coluiereiin,
        (In Conlangish friendship)

        Shaul Vardi