I'm teaching a Bulgarian student English, and it is most instructive. As with all languages, there is a need to focus on vocabulary, grammar and usage, all of which are beautifully exemplified in Clare Balding's writing.
Learners of English, however, also need to put stress and intonation in the right places, in words, phrases and sentences, and we have been practising this using Clare Balding's book. Clare's reading of it (Penguin, £20, but I found it for £10 on Ebay) is wonderful for this purpose. Clare reads rather more slowly than some, and the intonation is perhaps a little more stressed than in her tv commentating. This makes the phrasing and stress patterns crystal-clear to a person learning English who is no longer in the foothills. Altogether admirable, and my student loves it. I mean, really loves it. Dancing with joy loves it.