Q: When “etc.” falls at the end of a question, how should it be punctuated?
When "etc." falls at the end of a question, would it be punctuated with only a question mark (etc?), or with a period followed by the question mark (etc.?)?
Answer: Generally, in American English, if "etc." is used in the middle of a sentence, it is followed by a comma. However, if the word "etc." appears at the end of a sentence then the period (which is part of "etc.") serves as the final punctuation mark. On the other hand, if "etc." or any other abbreviation ending with a period appears at the end of a question, then you must use both punctuation marks (etc.?) Give more time for your research, spend less time formatting! Check out Editage’s Manuscript Formatting Services and get professional support for journal formatting. Related reading:
When writing scientific articles, the best thing is to avoid the problem altogether and never use "etc". Be scientifically more specific, and for example write "..........and other criteria".

