Do you mean because he didn't get the metaphor or because he said 'it moon' instead of 'it's the moon'? In either case, you could just as easily ask the same of anywhere outside the strict dictum of the Noel Coward play, a Merchant Ivory film or tea with the queen.

A fully functioning language could be taken as one which allowed people to communicate effectively so there's your answer. But regarding Gambian communication in general, I often wonder how different tribes manage. Do they use a lingua franca or rely on a skeleton of other languages?

Opposite to Senegal, where 80% of the people can speak wolof, there is no lingua franca in The Gambia. English is the official langage, but only people, who attended school can speak it more or less, depending on how long they went to school.

I have no knowledge of the other languages, but Wolof and Mandinka have no similarities, so one can not be used to learn the other one.

just going off at a tangeant, thankyou jo for repeating the highwayman. i hadn't heard that poem in years and the years slipped away as i read it again

Watchout for ostlers though!!