If you say
that someone won't be long
, you mean
that you think
they will arrive
or be back soon
. If you say that it won't be long
before something happens
, you mean that you think it will happen soon.
'What's happened to her?'—'I'm sure she won't be long.'
If every tune from Radiohead is as good as this one is, it can't be long before they
are household names.
COBUILD Advanced English Dictionary. Copyright © HarperCollins Publishers