while I've been prepping for the SAT using The Ultimate Guide to SAT Grammar Workbook by Erica L. Meltzer I encountered this question:

Sentence: Before a vaccine was finally discovered by an American scientist Jonas Salk in 1955, more than 80% of polio patient received help from the foundation



  2. Scientist Jonas Salk,

  3. Scientist, Jonas Salk

4. Scientist, Jonas Salk, (right answer)

Comment: why isn't the right answer is B since we don't know who the scientist was so it's essential info, also we have before

  • The test is meaningless with only the information provided. Is there more than one American scientist in the group being discussed? Is there more than one American scientist named Jonas Salk? There is also a certain level of intention that can only be determined by the author of the sentence. In many ways, the punctuation itself determines, by definition, if something is restrictive or not. Unless the person answering the question is the author, the answer is subjective. The only objective answer would be which is the more common interpretation. And, for that, there should be evidence. Aug 4, 2019 at 19:48
  • Because an is there, you need the commas around the name.
    – Xanne
    Aug 4, 2019 at 20:47
  • Note that whether it’s essential depends not on meaning or the importance of the information, but only the grammatical structure of the sentence.
    – Xanne
    Aug 4, 2019 at 21:08
  • 1
    @Cascabel: You're right. This should be closed as a duplicate. Unfortunately, at the moment, my close vote (cast just now) is the only one that cites the dupe question that you have noted. Thank you for pointing out the prior question. Also, anyone who can change their close vote reason from "primarily opinion based" or "off topic because..." to "duplicate" should do so, as that is a more accurate close reason and will be more helpful for future visitors to this page..
    – Sven Yargs
    Aug 5, 2019 at 22:39
  • 1
    @Cascabel: That's a silly and unnecessarily constricting limitation by Stack Exchange, in my opinion. Sorry about the dead-end advice—but thanks again for pointing out the duplicate.
    – Sven Yargs
    Aug 5, 2019 at 22:51

1 Answer 1


The point of the question is not to set history straight but to test one's understanding of parenthetical commas.

Each answer differs in the placement of commas so as to set off the name of the scientist for special consideration. If you imagine the sentence read out loud you can hear how the commas function as pauses in speech to describe secondary details within the text. This can help with comparing one answer to another.

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