Twig it. Several readers pointed out, following my note last week, that some reference works, notably Collins Dictionary, give the Gaelic word tuig, meaning “I understand”, as a possible source of the idiomatic sense of twig. Others noted that twig more often means to come to a sudden realisation rather than simply understand. So it’s equivalent to catch on, and to another British and Commonwealth idiom, the penny dropped (from a penny-in-the-slot machine). As James Forder pointed out, one doesn't twig the theory of relativity. But a person might twig that he was being made fun of. And Dorothy twigged that she and Toto weren’t in Kansas anymore.

Footloose and fancy-free. I wrote in the piece last time that fancy had lost its association with physical attraction. I was thinking of the noun. The verb still has this sense, of course, as in “I really fancy him”, and the noun can have it in phrases like “He took a fancy to her”.

Mailing problems. A transmission error meant that more than 4600 subscribers failed to receive the email issue of 23 August. I would have posted a note about this on the website, but the problem also stopped me receiving error reports. Though the issue persists I hope a work-round will ensure everybody gets it. If you missed last week’s issue you can read it online here.