We understand that language changes, more or less slowly. But if it changes, how can we be really correct? How can we avoid the putdown, the disrespect that comes with seeming uneducated, careless or insensitive?
Lynn's family included people learning English instead of Finnish and learning English instead of Swedish and Spanish. They all wanted to speak the local language well and effectively. Besides, Lynn has a good ear for vowel sounds. She is very alert to the different between "shut" and "shot". We both found that vowels, especially some "o" sounds differed between Maryland and Wisconsin. "Cow" and "no" stood out.
I like to look up any question or subject in Google, no matter how weird. So, I looked up "dropping ly from adverbs". We both have been getting in the habit of adding "ly" to all our words to compensate for the fewer and fewer uses of "ly" we hear. "Drive safe" makes us say or think "ly" as in drive safeLY.
Google put me on to this essay which I read to Lynn:
https://www.visualthesaurus.com/cm/wc/when-adverbs-fall-flat/
Prof. Vishton gave a great example of how our ears and brains combine to learn language without explicit instruction. "I am going bowling" is ok but "I am going Ohio" is not. We weren't taught this but we learned it by repetition and consciousness and brain power.