Discussion Groups / English Usage / January 2004

'all that' points to something a little more extensive than 'that'.
If you heard a loud noise, you wouldn't say 'What was all that about?'
If you heard a series of various noises that swelled up, persisted a
few seconds, and then faded, you might use 'all that'.
--
john

First:  the thing referred to is appears to have a complex explanation
or significance.

Second:  the thing referred to itself is something complex, and has an
explanation or significance.

Third:  this sentence has a certain je-ne-sais-quoi, but I don't know
what it is.