Aymara's time line

[Elizabeth Traugott]

Ellen Contini-Morava mentioned Clifford Hill's work. It is:

Clifford Hill, 1978. Linguistic representation of spatial and temporal
orientation, BLS 4: 524-538.

I myself suggested in the same year that while deictic tense is 
typically
back (past)-front (future) oriented, relative (sequential) tense is
typically earlier (front)-later (back) oriented, i.e. they are
oriented in opposite directions (If winter comes, can Spring be
far behind?), see:
1978. On the expression of spatio-temporal relations in language. In 
Joseph
Greenberg, Charles Ferguson and Edith Moravcsik, eds., Universals of 
Human
Language, Vol III: 369-402. Stanford, CA: Stanford Univ. Press
and
1985. "Conventional" and "dead" metaphors. In Wolf Paprotté and René 
Dirven, eds.,
The Ubiquity of Metaphor, 17-56. Amsterdam: Benjamins.

It would not be too surprising if a relative system were 
grammaticalized into a deictic one,
if indeed that is what the Aymara system is. But I don't think that is 
necessary--as Hill
showed, there are two ways of orienting oneself: face to face, or in a 
line.

Elizabeth Traugott