Abstract: How do stars form? This is not just an interesting question in itself, but star formation also sets the initial conditions and environment for planet formation. Many (probably most) stars form in binaries and so the properties of binary systems should contain a lot of information on the star formation process. Unfortunately, many binary systems are destroyed by encounters in star clusters and so rarely do we see the primordial binary population. I will talk about how we can use binaries to probe star formation, the problems associated with this, and what we (or at least I) think are the conditions in which many stars and planets form.