Another thing in addition to CODPIE that's oft occured to me as a SLF is the sitting of NESBoes at the exits of an english only flight (such as QF). They
1. Generally will miss some aspects of a printed instruction on one reading
2. Tend not to understand commands at times of stress (and when is an evac not?)
3. Tend to say "yes" when asked anything whether understood or not.
This is with all due respect: my day job is with predominantly mandarin speaking people although the language used is english: great guys and their english is a 100x better than my mandarin. Take it the other way: would I think it appropriate putting me overwing on an internal China flight?
Pax at emergency exits must be fluent in the first language likely to be used in an emergency in that flight