Michelle Obama gives a masterclass

The First Lady of the United States is known as an internationally powerful advocate and leader on key issues such as girls' education.

Less commonly, she is cited as every bit as good an orator as her husband.

Like his, her style surprises the listener in being disarmingly informal. Like him, she uses this informality – and the credibility it affords her - to make powerful points which cut directly to the issues she wants to address. She appeals to us directly, setting aside the mantle of office and privilege with her intimate tone and informal syntax.

An excellent case in point is her recent speech to Fortune’s 50 most powerful women summit. On the surface, this is a speech about empowering the leaders in the room to act to support her key cause of girls’ education.

The First Lady's rhetoric takes her arguments step further, making every listener in the audience, regardless of their age or background, complicit with her. Using short sentences and unconventional grammar and punctuation, she breaks up her points with humour and rhetorical touches – FLOTUS is not above the odd raised eyebrow or in-joke to help her point hit home.

It works: by the end of her delivery we don’t just think she’s right – it feels as though we, her audience, are making the plea for girls' education alongside her. It is a deceptively powerful technique. Read the full speech here.