  We are on the verge of the first precision testing of the inflationary
cosmology as a model for the origin of structure in the Universe. I review the
key predictions of inflation which can be used as observational tests, in the
sense of allowing inflation to be falsified. The most important prediction of
this type is that the perturbations will cross inside the Hubble radius
entirely in their growing mode, though nongaussianity can also provide critical
tests. Spatial flatness and tensor perturbations may offer strong support to
inflation, but cannot be used to exclude it. Finally, I discuss the extent to
which observations will distinguish between inflation models, should the
paradigm survive these key tests, in particular describing a technique for
reconstruction of the inflaton potential which does not require the slow-roll
approximation.
