We found that if we remove the extraction line and the desorption line, it will turn into a much more simple system.

Do I need the second "the" in this sentence?


There are different ways of phrasing it with slightly different meanings:

the extraction line and the desorption line

  • There is 1 extraction line and 1 desorption line.

the extraction and desorption line

  • this is also correct English, but means that there is 1 line which is both the extraction and the desorption line

the extraction and desorption lines

  • this could mean the same as the first way, but it is possible that there is more than 2 lines here; e.g. 3 extraction lines and 1 desorption line.
    In your context it's probably already clear that there are only 2 lines, so this sentence would be fine.

For example:

I'll take the red jacket and the blue jacket

  • I will take 2 jackets, 1 red jacket and 1 blue jacket

I'll take the red and blue jacket

  • I will take 1 red and blue jacket

I'll take the red and blue jackets

This could mean any of the following, depending on the context:

  • I'll take 1 red jacket and 1 blue jacket
  • I'll take some red and blue jackets
  • I'll take some red jackets and some blue jackets
| improve this answer | |
  • I think you meant to remove the second and from your third example. – Davo Apr 21 '17 at 13:08
  • where do you mean sorry? I could be being stupid but I only see 1 and – Some_Guy Apr 21 '17 at 13:12
  • My mistake. I meant remove the and - otherwise, your second explanation of the third example doesn't make sense. The red and the blue wouldn't refer to one jacket with both red and blue. – Davo Apr 21 '17 at 13:13
  • @Davo That's it, thanks. It's hard to notice mistakes in something you've already read a couple of times, I find my mind sort of autocorrects to what I meant to type after a while. I need some sleep hahaha – Some_Guy Apr 21 '17 at 13:49
  • 1
    @Davo it's a pain. I usually just put &nbsp; (no break space) or a <nothing> tag in or something. People have been complaining about this at meta stack for years – Some_Guy Apr 21 '17 at 13:51

You don't need it, but it will be clearer if you include it.

If you omit it, there is a possible interpretation that "extraction line and desorption line" is interpreted as one single item rather than two. This is probably not very likely, because of the repetition of "line", and it may be that readers' knowledge of the subject would make it even less likely; but you can avoid any risk of misunderstanding by including the second "the".

| improve this answer | |
  • In that case you'd need to say "the extraction and desorption lines" no? – Some_Guy Apr 21 '17 at 9:49
  • That would be more normal, @Some_Guy. That's why I say the misinterpretation is not very likely. But it would remove any ambiguity if you repeat "the". – Colin Fine Apr 21 '17 at 10:39
  • From context, people would likely understand anyway, but it's not a matter of style or preference, saying "the extraction and desorption line" to mean 2 lines is incorrect. "John has a black and white dog" never means 2 dogs, it means 1 dog. In order to refer to 2 dogs you would have to say "John has a black and a white dog" or "John has black and white dogs" – Some_Guy Apr 21 '17 at 11:06

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.