 Now Twin Oscar, being an exact duplicate of Earth’s Oscar, will have many of the same properties Oscar has. For instance, he will be disposed to accept a sentence of Twin English that is written and pronounced exactly like the English sentence “Water is wet.” However, Putnam argues, Twin Oscar’s word ‘water’ does not refer to water. There is no water on Twin Earth, only XYZ; Twin Oscar has never seen water, talked about water, or interacted with water in any way. So it seems that he cannot possibly refer to water.