make sure表示“弄确实；核实；查证”。make sure常用于祈使句，后面常接that宾语从句或of介词短语。

1.Make sure that从句意为“弄明白；确信"。

2.Make sure of 代词/名词，意思也是“弄明白；确信”。例如： — Make sure of his coming before you set off. — 出发之前要确定他是否来。 — I make sure (that) he would come. — 我确信他会来。