One is in the past tense, and the other is in the present tense, with the perfect construction. There is no difference in meaning, and both are grammatical. But they would be used in different contexts, at different times.
– John LawlerSep 19 '20 at 15:37
(1) is suitable for a narrative where everything is reported in past tense, for instance _That was something he never did before and never did again._ (2) requires a narrative stance from the present, or at least the time the narrator has established as the present. _When faced with something he has never done before, he usually stops to decide ways and means_.
– John LawlerSep 19 '20 at 15:54
The presence of the word ***never*** doesn't really affect the situation here. ***He did it before*** works fine in narrative contexts set in the past OR present, but ***He has done it before*** requires a narrative context centered on the present moment / time of utterance. The standard principle being that Present Perfect implies a ***past*** action that's somehow strongly connected connected to the ***present***.
– FumbleFingersSep 19 '20 at 16:11
Are the two forms interchangeable in practice when used in the present?
_Now he does something that he never did before_
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_Now he does something that he has never done before_.
– Victor DubrovskySep 19 '20 at 16:15
@VictorDubrovsky No, those two are both ungrammatical; the following forms are ok though. *Now he is doing something he has never done before.
He was doing something he had never done before.
This is the first time he has ever done this.
This has been the first time he has ever done this.
That was the first time he ever did this.
That was the first time he had ever done this.
That had been the first time he ever did this.
That had been the first time he had ever done this.*
– tchristSep 19 '20 at 16:43
Also: *It had been the first time I saw the ocean.
For the first time, Asian giant hornets have been spotted in the United States.
The first time ever I saw your face I thought the sun rose in your eyes.
This was the first time that he had ever looked into the labyrinth of the human soul.
If this had been the first time to Bishop’s it would have been the last.
Pericles was included among those seven plays, that being the first time Pericles appeared in a collected edition of Shakespeare’s works.
The Queen has been photographed outside Windsor Castle, the first time she has been seen.*
– tchristSep 19 '20 at 16:45
1
@tchrist I think you could write "Now he does something that he has never done before." grammatically in a historical or narrative present sentence.
– Jack O'FlahertySep 19 '20 at 17:39