Halliday & Matthiessen (1999: 111):
There are two consequences of this. The first is that, in quoting, the form of wording is still that of the first-order realm of experience: "Shall I feed the cat ?" — taken by itself, there is nothing about this to show it is a projection. In reporting, on the other hand, the form of wording is clearly marked as being of the second order: whether she should feed the cat has lost its first-order semantic features — and hence has to be projected by words that specify its particular speech function: asked/wondered, not said/thought.