英语里到多少岁用的是turn,比如 As soon as he turned 15,he left home.他一到15岁就离开了家.
grow一个是不跟岁数搭配,再者,即使一定要用grow,也只能说 grow up to XX 岁（但这样的表达已经相当不地道了,只是较为合符语法而已）.