My good friend is from Pittsburgh and frequently uses the word whenever to mean the word when. I am aware this is a regional dialect and really wish to respect that, but it is causing numerous problems in our spoken communication. (I am also a native English speaker but am not accustomed to this usage of "when" and "whenever".) I have expressed my concerns to him and asked him to use a neutral dialect to improve communication, but he argues it is valid English, he doesn't understand the difference between the two anyway, he "doesn't have problems with anyone else understanding [him]", and that my misunderstandings are because I "have Asperger's and understand [his] speech literally". (I would guess if no one else has an issue with his speech, it's because he speaks English primarily with people who have the same regional dialect and non-native English-speakers and uses French and German for work. That said, perhaps everyone else does understand what he means without any confusion. When I ask for clarification, he gets irritated.) What should I do?
Examples of such misunderstandings are below:
Example: Whenever my aunt was about to die, she called me into the
room and told me she loved me.
I understood this as his aunt periodically became ill to the point where she was close to dying and called him into the room to say she loved him. (My background in healthcare makes this seem like a very plausible situation.) I responded to him in a way that reflected my understanding of the habitual nature of this.
He was annoyed and said it was obvious that the aunt was about to die one time and that, as such, this calling-into-the-room was a one-time occurrence.
Example: Whenever my sister was born, my dad fainted.
It is obvious to me that his sister was born one time. In this instance, although I believe the better word choice is when, I can understand that his father fainted when his sister was born.
Example: Whenever I moved to Germany, I lived in Berlin.
I knew he had moved to Germany once for a (temporary, location-based) job. However, his statement surprised me, and I thought maybe I was wrong (and as a friend I wanted to learn more if he had actually moved numerous times), so I asked how many times he'd moved to/lived in Germany. He was equally surprised by my question, responded he'd moved to Germany once, and could not understand how there could be any confusion in the statement.
Best Answer
As Wikipedia says, "all scholarly research in linguistics is descriptive."
What you reported are good examples of the "punctual whenever", which is a grammatical feature of Western Pennsylvania English that differs from General American. Wikipedia cites Montgomery, M. B. (2001). "My mother, whenever she died, she had pneumonia": The history and functions of whenever. Journal of English Linguistics 29(3): 234-249. and provides these details:
The examples would be incorrect grammar in General American, but it seems your friend isn't trying to speak General American---he indicated that he's happy with the way he already speaks, and doesn't want to explore it further with you.
What should you do?
Option 1: Continue asking your friend for clarification when he's not in the mood. (not recommended)
Option 2: Accept that your friend uses "whenever" in this way, and remember how this works in his dialect whenever you hear him use "whenever" and want to know what he means.
Option 3 (my recommendation): In addition to option 2, become an amateur (or professional) linguist by reading articles about Western Pennsylvania English, so you can relish in recognizing many more grammar quirks your friend may use which you may not have noticed before. Post questions about them here or on linguistics.SE if you're so inclined.