*es- or *h1es- ?

modelo1
Saluete!

I started to read about PIE just about two weeks ago, and I feel hard to
be sure of something, as I always find a different opinion about anything I
read. For instance, I was convinced that the root for the "sum, esse" in
Latin was *h1es-, at least in the present. Ok then. But then I saw the
Pokorny dictionary, and there it's plain *es-. The dictionary is old, it's
possible to be wrong, I thought. Well, in this list's files I read *es-
again. Now i'm the face of despair : ). Please, someone can explain what
arose such discordance, and which opinion is true?

For me, in all my highness of two weeks of reading, the *h1es- root
seems a little more comfortable, for it can allow the loss of -e- on the
plural persons on present, and still allow to have es- in Latin and Greek,
for instance:

h1és-mi
h1és-si
h1és-ti
h1s-vos
h1s-th2eh
h1s-tes
h1s-més
h1s-th1é - estis - esté
h1s-énti

(singular, dual, plural)

But then I saw the vedic conjugation of this:

ásmi
ási
ásti
svás
sthas
stas
smáh
sthá
sánti

And I realised that the a- before the -s- of the root disappeared, as if
the PIE root was *es-, becoming *s- on the dual and plural of the present.
Again, I'm not even sure if PIE has a dual conjugation : ). If anyone knows
a good book about this, please tell me too...

Valete,

Edgard Bikelis.