In the summary of my physics paper, for a scientific journal, in the start of a new paragraph in the discussion, what is more correct to write?

We have showed that the system obeys this and that rules, …


We have shown that

or simply:

We showed that

4 Answers 4


In the abstract to a scientific paper - at least in my field, statistics - you might use the simple present: "We show that ...".

In the discussion, the logic of using "we have shown..." is that you are referring to something in the past that stopped recently but has an influence on the present (which is this context is the present moment you are sharing with the reader of the paper).

If you said "we showed..." then the reader would expect that to refer to your previous paper, not to the one he is currently reading.

  • Great. So from yours and the previous answer, I can conclude that "we have showed" is simply WRONG, and "we have shown" fits better in this context than "we showed"? Right? Feb 21, 2018 at 15:57
  • 1
    It strikes me as wrong, but I doubt whether it is 'simply' wrong. There may be those who would use it, and defend it. But I advise you not to.
    – JeremyC
    Feb 21, 2018 at 16:35

As a native Irish-English speaker I'd say "We have shown". I'm not 100% of the legalities of why that is, but "We have showed" is just as hard to pronounce as "a apple".

If you're reading the paper back, it's much easier to read "have shown" than "have showed".

This might help with the technicality side of it.

  • 1
    Thanks, but what is the benefit of using "We have shown" over "We showed" then? Why use past-perfect (is the first option really past-perfect?)>? Feb 21, 2018 at 15:42
  • The link you provided, if I see correctly, does not use this verb in the context of "showing that" something happened. It also does not show an example in plural.. I am not sure it answers my question. Be happy if you correct me on that. Feb 21, 2018 at 15:49
  • Sorry, I was just addressing the first two points in that answer. You could say that "you showed" and it would be correct, but it more depends on the full context of what you're trying to say. In your case it depends on what version of verbs you are using throughout the rest of your report. If you're mainly using "we have done x" rather than "we did x" I would recommend just sticking to either case. I tend to write my reports(Computer Science) using "we did x" as it tends to work better for explaining steps, whereas "have done x" works better for conclusions. Hope that helps somewhat.
    – Andre
    Feb 21, 2018 at 15:51

You seem to be asking about the correct simple past or past participle form. Wiktionary says the following about show:


  • third-person singular simple present shows
  • present participle showing
  • simple past showed or shew
  • past participle shown or (now rare) showed

(formatting altered for clarity)

So the following are all correct but some are more commonly used than others:

  • We showed that ... (simple past)
  • We have shown that ... (past participle - common usage)
  • We have showed that ... (past participle - rare usage)

As suggested, the abstract of a thesis should probably say "We show that ..." However, in ordinary usage, "have shown" is just a hair more elegant than "showed". If you strive to show elegance, use it. If you are looking for down-to-earth dialog, then "Yesterday, Sam showed me a picture of his girl-friend."

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