Afterschool,Ipalysoccerwithmyfriendsonehour.填空.那请问为什么Mymotherworksonehour.不用加介词for呢?回答！

Question

After school,I paly soccer with my friends _____ one hour.填空.
那请问为什么 My mother works one hour .不用加介词for呢?
回答！

Answer 1

For 是介词,可表示很多意思,在此句中表时间长度,这种用法在完成时的句子中尤为典型,例如：
I have learned English for six years.我已经学英语6年了.
He had been living in Shanghai for ten years by the end of last month.到上个月底他已经在上海居住10年了.