Use of "after"

Posted by Doug Seaton on August 08, 2003

An expression often used by my (Scottish) grandmother was "I'll (or You'll, or He'll, etc) be after" - e.g. "I'll be after a trip to the shops", which I can remember my dad explaining as Scottish-english having inherited some Gaelic roots. As I recall, he thought it should be interpreted as something like: "I'll [eventually] be [in the state corresponding to] after [having had] a trip to the shops".
But this doesn't work for the expression used a few minutes ago by my (English) daughter: "I'm after a lift to town".
What is the real basis, and just how should such expressions be parsed?