On Alex Lascarides’ webpage, there is a paper on “Imperatives in Dialogue”, co-authored with Nick Asher, to appear in a volume on The Semantics and Pragmatics of Dialogue for the New Millenium.

BTW: If, like me, you look at such postscript files only after they’re converted to pdf-format, you may be disappointed at the quality of the onscreen display. That is because the postscript file includes so-called bitmap fonts. Printouts should be fine. There is at least one way to fix the postscript file to include the scalable and hence more easily displayed Type 1 fonts: if you have a working TEX/LATEX installation, you can use a program called “pkfix”, written by Heiko Oberdiek, to do the fixing for you. More on this at the TEX-FAQ.