Diagrams. Diagrams and processes are the least common types of Task I. There are three main types of diagram that you could be asked to describe. First is a diagram showing the component parts of something. For example, a light bulb, a tap or a photocopier. You are not being asked to say how these objects work, only to describe what is shown in the diagram. The second type of diagram is a map or plan. This could be the map of an area or the inside plan of a building. The third type is when you need to describe what something looks like. For example, a house. In many ways this is very similar to the first type of diagram, except the focus here is on describing the appearance rather than the constituent parts.