hang on有两种含义：
1.等等.如果你想让别人等一下,你可以说,hang on a second.
2.hang on还可以表达勉强进行,或勉强为生.比如,How are you?I am hanging on.这里表示“凑活”,或“马马虎虎”.
insist on表达的是坚持,一般是insist on something或insist on doing something,坚持某事,或坚持做某事.比如,He insisted on taking the bus.他坚持要座汽车.