I'm not sure what you mean, but I THINK you mean to say "of the same age", as in "Greg and Sue are of the same age" (meaning that they are as old as each other).
By or at a certain age are both correct, with slightly different meanings. We say by age six when we are thinking of a succession of years; but we say at ten years of age when considering that one time.
The grammatically correct phrase is "the same as hers".
Shoo-in is the correct spelling; but when you say either, both sound the same.
It is redundant to use 'exact same.'
yes, although it would be clearer to say you are mature for your age, or wise for your age. As given, the sentence suggests that you are are accountable for being 15.
By or at a certain age are both correct, with slightly different meanings. We say by age six when we are thinking of a succession of years; but we say at ten years of age when considering that one time.
It is not correct English to say "somebody has learned something from an early age" due to the use of "has".
No. If you are trying to say that you have the same opinion as another person, the correct way to say it is "I agree with you."
The grammatically correct phrase is "the same as hers".
That is not quite correct. We do the shopping, but we make the purchases.
Shoo-in is the correct spelling; but when you say either, both sound the same.
Correct is the same as it is in English. It means that it is free from error.
It is redundant to use 'exact same.'
Yes, there is a verb and and a noun and they are in the same tense therefore it is gramatically correct.
Neither, apparently, see related links.
The same age as scientists deem correct. About 4 billion years old.
the correct way to say Kwanzaa in spanish is "Kwanzaa"...