prep. 在...之後，遲於...，落後於，基於，追趕
例句：
Who is the girl standing behind Richard?
站在理查德後面的那個姑娘是誰？
The train was 10 minutes behind time.
火車晚到了十分鐘。
Britain is behind Japan in developing modern technologies.
在發展現代技術方面英國落後於日本。
The police were hard behind the escapees.
警察正在緊追逃犯。
adv. 在後面地，落後地，遲，不如
例句：
He caught up with the parade and walked behind.
他趕上了遊行隊伍，跟在後面走。
The lights of the city were left behind us soon as we drove along the street.
我們駕車沿著街道壹路疾駛，都市的燈光不久就被拋在我們後面。
You'll lag behind if you don't study harder.
妳要是不努力學習，就會落後的。
He didn't want to fall behind in his lessons.
他不想在功課方面落後。
I fell behind in my payments.
我付款逾期了。
She was never behind in offering advice.
她在出諫言獻策方面從不落於人後。