In a thread about Eleanor Farjeon's Morning has Broken the question arose whether she'd written blackbird or black bird. Of course it was the first, but it set me thinking about the difference a space can sometimes make.

For example there can be a world of difference between for ever and forever, or far away and faraway. And then there are the jokey things that come up in crosswords - leg ends and legends, or pull you up in department shops - men swear and women swear and even children swear.

But the first sort are what intrigues me, because it's quite hard to identify where the difference lies, and to explain why something that isn't there can change things that way.