In response to earlier comments, I think it's worth distinguishing between pronunciation and grammar. As an ESOL teacher I've been trained to give students a good grounding in grammar, but what I cannot pass on is "The Queen's English" in terms of pronunciation, because I don't have the required accent myself. There is nothing in either Trinity or Cambridge's TESOL course to say that I should, perhaps since the majority of native English speakers have accents other than RP. However, when it comes to the native speaker, I think there are all sorts of influences in play. I once worked (in academia) with a man who chose to cover his Edinburgh accent with something pretty close to RP, and it was quite a convincing act, but the occasional use of a word we wouldn't use in England, along with the odd quirk in his sentence construction, occasionally gave him away. I think most of us who worked with him would have had no problem with him using his natural accent or the odd grammatical quirk that was authentic to his background. Hence in spite of my training I don't condemn Alesha's less than perfect use of grammar - in fact I am sure I make the odd mistake myself here and there, especially in speech.