Since +r(sh)gc(din)wr(sh)gԏԁ(li)ġԺ Á(li)f(shu)(dng)ʼr(sh)g
I have been in Beijing since 2010.
For + r(sh)gΣÁ(li)f(shu)(dng)m(x)r(sh)gL(zhng)˾е^Z(y)(dng)~Ҳ(yng)ԓm(x)Ԅ(dng)~
I have been in Beijing for one year.
for +һΕr(sh)g
since +
since +һΕr(sh)g+ ago
since +r(sh)gc(din)
he has been dead for three years
he has been dead since three years ago
He has studied English since 2003
He has studied English since he was ten years old