for long与for a long time的区别
问题描述：
for long与for a long time的区别
答
for long和for a long time均用以表示时间,肯定句用for a long time,否定句用for long,只有和too,enough,as,so,seldom时表示肯定
We have been friends for a long time.
You have been waiting long enough.