insist
1.insist后面接on或upon。例如：He insists (up) on the importance of accurate pronunciation. He insists (up) on his innocence. 和He insists (up) on learning to swim.
2.insist后面接on或upon和动名词，不接不定式，如可以说He insisted (up) on going with me，不可说He insisted to go with me。
3.insist on或insist upon后面不可接宾语和不定式，如不可说He insisted (up) on me to go with him，该把me to go改作my going。
4.下面两句意思不同：
- He insists that she is careful. （他力言她是小心的。）
- He insists that she shall be careful. （他坚持她该小心。）
这两句里的insists后面都可以加上on（或upon）it。shall be改作should be，must be或be也可以。假使把insists改作insisted，第二句里该用should be或must be或be。
