Form and Materials
Clues to answering the question of what an object is can be found by really looking at its form (its shape, its parts) and the materials from which it is made.
Observe, hold and analyse the object, use what you find out to build up a sense of what it is used for.
Detailed shape and materials used to create the object differ according to its use. Examine that detail to get clues. Remember the example of the hammers in Steph’s first film. They are all essentially the same kind of tool, but they differ significantly in their detailed shape and the material they’re made from, depending on their specific use. So it follows that you can use that detailed shape and the material to determine that use.