In this case we would need to know the full sentence with the subject. For instance, if you say I have or I've...it would be correct to use gotten. However, although the sentence may be correct if you are using "have" in the sentence, the best way to say this sentence would be to eliminate have altogether. Then "gotten" would not be correct. You would say, "I just got back" or "We just got back". Usually when you are using have in the sentence (other than stating possession) than the use of "gotten" can be the correct usage for the word "got". In this sentence, since "back" is not something that is/was possessed, than gotten is the correct term if you are using "have" in the sentence. For example, if you were to say "we've gotten the answer", than that would be incorrect because it is showing possession. In this case you would want to say, "we've got the answer". There are many other rules pertaining to the use of gotten.
Yes
I have / I've just seen you do it. (so none of your variants).
The colloquial phrase is "most probably" and in correct grammar is just "probably."
In strict English grammar, the correct thing to say is "it is I." It is me is just more common usage.
I would say " I look forward to meeting you." instead of just " Look forward to meeting you." But as far as I am concerned it is just fine and I can be a grammar snob!
It is correct, but remember it also depends upon the context in which it is used. It is also correct to say a pair of scissors.Since scissors is plural, you can not say "scrissors" it is either a pair of scissors or just scissors.
I just got back, or I just returned would be better.
No, the correct grammar would be: "July has just started."
The correct grammar is "you have just been." This structure follows the typical order of subject (you) + auxiliary verb (have) + adverb (just) + main verb (been).
Yes. "The car that just passed was theirs" is grammatically correct.
The phrase "you and me" is not grammatically correct in traditional grammar. When referring to the subject of a sentence, it should be "you and I." However, in informal speech or certain contexts, "you and me" is commonly used.
The sentence "I got here just 2 minutes before their cut off time" is correct grammar.
For more than 20 years of existence i just now had the time to visit here is not a correct grammar.
I have / I've just seen you do it. (so none of your variants).
Yes, your grammar is correct. Your sentence "Just take care on your way home" is a polite way to tell someone to be safe while going home.
The colloquial phrase is "most probably" and in correct grammar is just "probably."
Patients' diabetes. (just spell or grammar check it)
"For so many years of existence i just now had the time to visit here" is not correct grammar "For many years of existence,I now have the time to visit here."