Is there any evidence of the usage of "although" changing?
To the best of my recollection, I have never seen the word "although" used at the beginning of a sentence as anything other than a subordinating conjunction, as in the following example: "Although her toddler will eat worms and dirt, he refuses to eat broccoli."** In terms of prescriptive grammar, I would consider this usage and punctuation correct as well as standard.
However, I have an extremely intelligent and well-educated student who claims that she has frequently seen the word "although" used at the beginning of a sentence as more of what I would call a conjunctive adverb. She would use the word "although" at the beginning of a sentence just as I used the word "however" in the previous sentence, and she would punctuate it accordingly. In fact, she claims that she was taught this usage and punctuation at her previous college.
Have you seen any evidence of the usage of the expanding? If she's correct, is that additional usage a new addition to English? It reminds me of the current slang usage of "because" as a preposition, which has begun to become popular in the late 20th and early 21st century by young Millennials, especially on social media sites like Tumblr. I often see the following usages:
"I was at IHOP because reasons."
"He voted against the bill because Obama."
Please enlighten me on this potential change in usage if you have the time. Thank you for your time and consideration.