Forum: ell.stackexchange.com
Tags: <present-perfect><present-simple>
Title: Proper tense in "I've tested the program with this input data and it works"
Question: Let's consider the conversation:    This program doesn't work with this input data.  I've tested the program with this input data and it does work.    Is it right to  use the present perfect here? Or does the simple past sound more natural?    I tested the program with this input data and it does work.    I suppose both variants are correct, right? But which one is more natural?

Answers:
sents: text: While both tenses are idiomatic and correct, the choice between present perfect and past generally depends on the context.
text: If you had recently tested the program, you would be more likely to say
text: I have tested....
text: If your statement related back to a test that you had carried out in the past (whether last month, last year or whatever)
text: you are more likely to say
text: I tested....
text: With the use of the past tense, one frequently gives the approximate date.
text: I tested the programme last week/month/year
text: and it does work.
answer_details: author: ell.stackexchange.com/users/41356/Ronald Sole
score: 9
sents: text: I wouldn't find either statement obviously wrong, or expect a native speaker not to say one of them, but they seem subtly different.
text: To me, saying: I've tested the program with this input data and it does work.
text: emphasises that the program is, right now, in a tested state.
text: Whereas:
text: I tested the program with this input data and it does work.
text: emphasizes a past event - you testing it.
text: For that reason I'd prefer the first if you wanted to keep the '
text: and it does work', and simply 'I tested the program with this input data' (or 'I tested the program with this input data and it worked', or
text: 'I tested the program with this input data this morning and it worked')
text: if you were not sure that it still worked now.
text: I speak
text: British English - US English seems to use the present perfect tense less often, so you may get different judgements from Americans.
answer_details: author: ell.stackexchange.com/users/87102/Alex Hayward
score: 6
sents: text: Both are right but to me, this is more natural:
text: I have tested the program with this input data and it works.
answer_details: author: ell.stackexchange.com/users/109564/Daniil
score: 3
sents: text: The perfect aspect is used to indicate the state relative to some other time; in the case of present perfect, that time is now.
text: So "I have tested" implies that while the testing was done in the past, it remains relevant, allowing one to follow with "it works" in the present tense: the act of testing was completed, and remains completed.
text: Using the simple past put the action purely in the past, and doesn't imply anything about the current state; the simple past doesn't have the same connotation of it being completed as the present perfect does.
text: So following it with the present tense is off; it should be "I tested it
text: and it worked".
answer_details: author: ell.stackexchange.com/users/61500/Acccumulation
score: 2
sents: text: This is a computer-programmer's opinion, rather than a linguists answer , but I would only ever use
text: I tested the program with this input data and it worked .
text: (Emphasis added for clarity.)
answer_details: author: ell.stackexchange.com/users/87109/ShapeOfMatter
score: 1

Summary of the answers:
While both tenses are idiomatic and correct, the choice between  present perfect  and  past  generally depends on the context.  "I've tested the program with this input data and it does work" emphasises that the program is, right now, in a tested state. Using the simple past put the action purely in the past, and doesn't imply anything about the current state; the simple past doesn't have the same connotation of it being completed as the present perfect does.
Both are grammatically correct and idiomatic, but subtly different in meaning. The perfect is used to refer to the tested state of the program, and the fact that the testing is complete. In contrast, the past tense refers to an action in the past, and does not necessarily imply that the program is still in a tested state.