Words and Formulas in Quantum Field Theory: Disentangling and Reassembling the Basic Concepts for Teaching

We address some problems related to teaching Quantum Field Theory (QFT) at the university level. After a discussion of the pros and cons of the canonical quantization approach, we present an alternative teaching proposal. The novelty of this approach rests on the idea of using a multilevel structure, where the levels of phenomenology, formalism and interpretation are related but distinguishable. In this context, the quantization of the electromagnetic field, which is taken as a paradigmatic case in the standard approach, is addressed as a special case and studied only in the last step.