This is an advertisement from an English tutorial centre that I saw in the paper today.
I find this advertisment quite funny. If Tann wished to emphasise the fact that she was a native speaker, why did she say the second part of the sentence in Cantonese? If she wanted to sound friendly, why didn’t she say the whole sentence in Cantonese?
Sure, a lot of advertisements today use mixed code. But given the service they are selling (English courses), and the point they wish to emphasise (the tutor is a native speaker), this slogan has a somewhat comical effect!