My grammar book suggests that when using words like just, that you should “always” use present perfect. So the correct form should be I’ve just arrived according to my book.
Is this true?
I ask because I see a whole lot of people using I just arrived all over the place. I therefore cannot help but wonder whether this is an incorrect form that is somehow nonetheless in wide use by native speakers, or whether it’s also a correct form just with a subtly different meaning.
Neither. This is a case (one of many) in which the two forms are equivalent in meaning.
This is aided by the fact that in English the two sentences are pronounced identically, since the /vdʒ/ cluster in /ayvdʒəstə’rayvd/ I’ve just arrived is very difficult to pronounce, and is normally shortened to just /dʒ/, which makes it indistinguishable from I just arrived.
Since people hear them identically, they are apt to spell them identically, especially if they mistakenly believe, as many do, that English spelling represents English pronunciation.
The same phenomenon is responsible for such confusions as I would of gone vs I would have gone, I got a cold vs I’ve got a cold, etc.