relative tense and beyond!

>I was thinking perhaps of adding some sort of indicator of perfection or
>imperfection of the action.  Past and futurity could be indicated, as you
>say, lexically if necessary; or they could use the perfect tense as a
>rough-and-ready past (much as Biblical Hebrew does).

JG -- I don't see why not.   Actions can be completed in both the vivid now
or in realms-of-what-is-not, like the past, future, dreams, hypotheses, etc.

>I'm thinking agglutinating here, perhaps based off of some Native American
>languages.

JG -- Strange, though I've never contemplated making an agglutinating
conlang, it seems to me that agglutination would be pretty elegant from a
conlanger's perspective.    No need for tables, tables, and more tables as
in highly inflected languages.   No need for complex clause constructions
that you need to free up word order in isolating languages.

I guess what I'd watch out for first thing with an agglutinating conlang is
lists, lists and more lists of functive morphemes, and any restrictions on,
or meaning changes resulting from, changing the order of said morphemes.

The latter issue becomes more significant if you decide to chuck the
potential for free word order and make your agglutinating grammatical
morphemes part of a language with LOTS of bound morphemes:   say, one or two
phonological words per clause or sentence.

Others could point out a lot more options:   your ultimate choices and
creations will be interesting.

Jim