I'm an English learner and I've never been good at grammatical rules or other technical sides of English. However I need to learn them in order to graduate. And on my way to it, I'm taking a class in which we're learning about vowels and phonetic transcriptions of them. (I feel the need to clarify that we take RP - Received Pronunciation or British English - as basis)
What confuses me is that our instructor gave these two words ("date" and "diet") as an example for homophones. He said that these words are pronounced the same but differ in meaning. As far as I know, when we pronounce diet (/daɪət/), we're using an "a" while date (/deɪt/) doesn't include it.
I've been thinking that his teaching experience of decades would be superior than my knowledge, but I am really confused. Is it safe to say that my instructor has a wrong idea?