意思上区别
make sure 一般用在句首,前面美有主语，表确定，证实；而be sure 前有主语，一般为sb. be sure to do sth./of sth./that
be sure
确信,肯定
I can't be sure.
我不能肯定。
make sure查明; 设法确保, 确定
You must make sure of the time and place.
你必须把时间和地点弄清楚。
Make sure at least two people from the marketing team can attend.
要确定销售部门至少要有两个人来参加。