My native language is Dutch. We have a subtle, but useful way of combining the ingredients: Prefix (+ comma) + and + Prefix + stem. However, I do not know whether the same rules apply in the English language, e.g.:

"Copper-, and iron-based materials" This means two or more materials. One or more based on copper, and at least another one based on steel, or vice versa.

"Copper- and iron-based materials" This indicates multiple materials composed of copper and iron.

Thus the comma makes the difference. Furthermore, the hyphen is necessary. And last but not least: "copper-based materials and iron-based materials" does not make useful use of the rules of language.

So what are the rules?

Thank you,


  • That is what we call the Oxford comma. Use as you wish, it's just a personal choice. Jul 26 '19 at 12:24
  • I've never heard of any such distinction. To me, copper- and iron-based materials means that the statement refers to both materials based on copper and materials based on iron. Jul 26 '19 at 12:26
  • Possible duplicate of How to use hyphens appropriately when listing multiple hyphenated terms? The use of the comma is inappropriate here (though in a list, which OP does not ask about, the listing comma is used in a predictable way). Jul 26 '19 at 13:18

I would say that

copper-and-iron-based materials

describes materials based on both copper and iron, while

copper- and iron-based materials

means two or more materials, some based on copper and some on iron.

Adding a comma to get

copper-, and iron-based materials

wouldn't change the meaning, since copper- and iron-based materials already has the meaning that the comma gives it in Dutch. You wouldn't include the comma in an English sentence unless it was a list of length at least three, such as

copper-, iron-, and lead-based materials.

In this case, the commas don't change the meaning.

Certainly copper- and iron- based materials means two or more materials, some based on copper and some on iron. See this website, which says:

Suspended Compounds

With a series of nearly identical compounds, we sometimes delay the final term of the final term until the last instance, allowing the hyphen to act as a kind of place holder, as in

The third- and fourth-grade teachers met with the parents.
Both full- and part-time employees will get raises this year.

  • The OP was asking whether the presence or absence of a comma after 'copper-' affected the meaning. Jul 26 '19 at 12:42
  • @Kate: Added to my answer now. I was explaining how to distinguish the two different meanings in English, but I clearly also should have said that we don't use commas like that. Jul 26 '19 at 12:51

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