lend是借出去(借给他人,用lend sth to sb.表示),borrow是借进来(从他人那里借某东西为己方所用,用borrow sth.from sb.表示).
eg.1.I lent him a pen.==I lent a pen to him.
2.I borrowed a pen from him.
动作发出的主体不同
borrow 常和from搭配,他是由借者发出的动作
e.g:Mary borrowed a english from her classmate.
lend常和 to 搭配,他是由被借者发出的动作
e.g:I lent my bicycle to my sister.
看例句就能很好的区别borrow和lend