This paper analyses the idiomatic expression “can’t make head nor tail” both in Latin and English. The cognitive analysis of these expressions (syntactic variations and use of other body parts in English), their content (these expressions involve spatial and ontological metaphoric schemata to indicate the abstract idea of coherence, generally referred to discourse) and their context (the tone is quite often colloquial) together with the study of the differences and common aspects between the Latin expression and the English one will allow us to inquire into the origin and development of each expression.