Is the sentence "Serving science since 25 years" correct?

Outside the advertisement context in which I saw this sentence I think you would say "We have been serving science for 25 years". In the shortened form "for" sounds wrong to me but "since" seems to be wrong as well because it should refer to a point in time, not a period.

  • 2
    The use of since in your example sentence is wrong. I don't understand what you mean by "shortened form". The use of for seems correct to me. Commented Dec 27, 2016 at 10:48
  • @CowperKettle I think OP means in the catchphrase Serving science for twenty-five years, the word for sounds wrong to them. This phrase is not a full sentence. Commented Dec 27, 2016 at 10:52
  • @Araucaria - then maybe they could write "25 years of serving science" or simply "25 years in science" - I mean, if they are trying to come up with a catchphrase. Commented Dec 27, 2016 at 10:53
  • @CowperKettle No, they should use for!!! :-) Commented Dec 27, 2016 at 10:57
  • It's not a full sentence, but it works fine as a tag line or slogan.
    – J.R.
    Commented Dec 27, 2016 at 10:58

1 Answer 1


We can think about periods of time or points in time. When we think about periods, we are thinking about a length of time. A length of time has duration. A period of time can always be used as the answer to a how long question. Here are some examples of periods of time:

  • twenty-five years
  • two centuries
  • five years
  • weeks
  • three and a half hours
  • hours and hours
  • five seconds
  • ages

All of the period phrases above can be used as the answer to the question How long did it last?.

We don't use since with periods of time. If we need to use a preposition in a phrase or sentence like the Original Poster's, we use the word for :

  • Serving science for 25 years
  • We have been serving science for 25 years.

We use since with points in time. A point in time can often be used as an answer to a when question. Phrases representing points in time sometimes appear with the word ago. Here are some periods in time:

  • Tuesday
  • last year
  • three months ago
  • 1984

Notice that we can use the phrases above as answers to the question When did it happen?

We use since with points in time:

  • since Tuesday/ last year/ three months ago/ 1984

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