What do I need to do for full marks on the question "describe an everyday circumstance where resonance occurs (4 marks)"?

It's important to look at the number of marks awarded for an answer, this can help you structure your answer and think about what will be on the marking scheme. Here a simple statement of an application of resonance would give you the first mark (such as a child being pushed on a swing). The second mark would be for recognising that for resonance to occur, you need a driving force (in the swing example that would be the parent pushing the swing at a particular frequency). The third mark would be for describing the situation in a little more detail (the swing oscillates about a central equilibrium and the child and the swing form an oscillating system that swings at a natural frequency when displaced and released). The fourth and final mark is to recognise how and why resonance occurs (if the parent matches the natural frequency of the swing with their pushes then resonance will occur and the amplitude of the swings will become larger).