Suppose a person born and educated in Greece comes to ancient Rome. They have learned Latin and can converse fluently, but not at a native level. What kinds of wrong pronunciation, vocabulary, or structures would the Romans be likely to hear?
Are there any ancient accounts of Greek idiosyncrasies in Latin? I am not asking about anything borrowed from Greek to Latin, but the kinds of mistakes the Greeks made when speaking Latin. I often speak English with people of various origins, and there are often clear hints about the native language of the speaker. Similar hints must have existed and been observed in antiquity. I am mostly interested in (written accounts of) spoken language, but observations about written Latin are also welcome.
The same thing from a different point of view: If I were to write a story in Latin featuring a Greek character, what kinds of quirks should I add to their Latin to make them feel authentically Greek?