Dave MacLeod wrote:
 > In the
 > sentence you gave as well (Tom said that yesterday) it's useful in
 > that even before you say yesterday you know that you're talking about
 > something in the past. It's certainly not useless and has nothing to
 > do with showing off.

It's not useless, but it's not very useful. Usually people have time to 
listen whole sentences. And they should! There are languages where 
negation word comes last. It would be dangerous to draw conclusions too 
early in cases like "I think you are very stupid not!"

 > Also note a huge difference between "Tom died
 > yesterday" (he's still dead) and "Tom was dead yesterday" (he's not
 > dead anymore). "Tom dead yesterday" doesn't tell you if he's back to
 > life or not.

It's is a matter of aspect, not tense. The problem is that English hides 
aspect behind tense. The same sentences could be expressed differently 
like this: "Tom dead since yesterday" and "Tom dead until yesterday". 
This is the type of tense marking that I'm advocating. It's more 
concrete than conjugating verbs.

Risto Kupsala