I think it is simple once you know it but to be fair it is not a very common name these days and if you were breaking it down as it is pronounced you could be forgiven for thinking the first syllable was spelt Dear and the the second syllable qas an I or Y like Kathy. After after all Kate and Katy are pronounced very differently and The ending of Katy sounds more like Deirfre than Kate does but which ends in a E?