Which is correct, please?
-It's a quarter past two.
-It's quarter past two.
Someone's told me both are correct, is that true?
I certainly say both. Americans might do it a bit differently. The other thing we say is "quarter of" in addition to "quarter to" or "quarter till."
2:45 = A quarter to 3, quarter to three, a quarter of 3, a quarter till 3.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Is the use of the present perfect correct in my sentence? :
"Someone's told me both are correct."
In the passive, I would use the present perfect, "I have been told", thinking of the present consequence,