Recently, I was given a copy of Complete Course of Japanese Conversation-Grammar by Oreste and Enko Elisa Vaccari. As it dates back to 1967, I was expecting at least a few things to be a bit old-fashioned – which is not to say that I, as a beginner, would really notice when they are – but I am enjoying it so far. I like the way the authors set the lessons out, and, at least to my mind, they explain the rules and features of the language in a very clear and readable manner.
Even so, I have a query regarding a passage from one of the earlier lessons. Just need some additional information, really. The authors say:
The nominative case is generally indicated by the particle wa ハ (postposition) placed after the subjective word. As a rule, the syllable ハ is pronounced ha, but when indicating the nominative, it is pronounced wa as in the English word waft.
In all the Japanese learning resources I have read up to now, I have only encountered は as the wa-particle. Given the age of this book, am I right in thinking that writing は is a modern convention? Are there still some circumstances in which the katakana form is preferred?