noun endings

[Leonel Hermida]

Hi,

Please forgive my ignorance but I have a few elementary questions
I would love to be responded to:

(1) One notices in Nauhatl since the very beginning that a huge amount
of nouns end in -(vowel)+tl (ehecatl, coatl, ocelotl, ticitl, cueitl,
tepetl, etc).
How much in those is noun root and how much is ending? And what is
the meaning of the ending? (definiteness?, gender?, distribution into
classes?, nominative marker?, singular ending?...)
(2) another very common ending, I mean "-tli" , seems almost as common,
a third being "-lli" and a fourth "-in"(and "ni"??); same questions as (1)
(3) why so common a noun as "innan" (mother?) appears to fall outside of
the 'rule'?
(4) In Teteoinnan (a divine name) the first part must be teo-tl (god), but
it appears reduplicated: is this a plural indicator? If so, how is
reduplication done? And is it common to make plurals that way? Is it the
rule?

I would be very grateful (for not spamming the list with trivialities), if
someone could indicate to me where on the web I can learn some grammar
and vocabulary. It is the classical language that interests me most.

Thank you very, very much.

Leonel