insist 用法与suggest 相似。insist作“坚持”说时，要用陈述语气；作“坚决主张；坚决要求”讲时，用虚拟语气。如：

When the son suggested that they should go to the park on Sunday, the expression on his father’s face suggested that he agreed with him.

当儿子提议星期天去公园时，父亲用表情表示了默许。

They insisted that he （should）be present at the ceremony.

他们坚决要求他出席这次典礼。

He insisted that he was innocent.=He insisted on his innocence.

他坚持说自己是无辜的。
insist
[in5sist]
vi.
坚持; 坚决主张; 坚决认为(on, upon)
坚决要求, 定要
insist on sb.'s innocence
坚持认为某人无罪
insist on a point
强调一点
insist on being present
坚持要求出席
I insisted on his coming with us.
我坚持要求他和我们一起来。
I insist that you (should) be present.
请您务必到场。
They insisted that she (should) be invited.
他们坚持要邀请她。
insist on
坚持; 坚决主张; 一定要
insist upon
支持