since VS for
He have had the piano______many years.
A. since B.for

the answer is B,why A is wrong?

thanks for helping !!!

Question

since VS for
He have had the piano______many years.
A. since   B.for

the answer is B,why A is wrong?

thanks for helping !!!

Answer

He HAS had the piano for seven years.

For + period...for seven years; for three days
since + point of time...since 3 o'clock; since yesterday

It's that easy!!!!