1.由demand, suggest, propose, request, insist, order由等动词引起的从句中，在美国英语中多用动词原形，在英国英语用“should+动词原形”：
He demanded that they (should) pay the money right away.
I suggest that we (should) cancel the trip.
She proposed that the meeting (should) be adjourned.
They insisted that the girl (should)b e sent to hospital.
2.在wish, would rather, had rather后的从句中，动词和虚拟从句中的谓语相同，需要使用动词的过去式:
I wish I were a bird.
How I wish it weren't raining!
I would rather they came tomorrow.
I had rather (that) you told her than I did.
I've loved you as if you were my son.
They talked as if they had been old friends.
He acts as if he was (were) the boss.
4.在it's (high) time后的定语从句中，谓语也需用虚拟语气，需要使用动词的过去式：
It's time we went to bed.
It's high time we stopped this practice.
It's time that they were taught a lesson.
5.在suggestion, proposal, order, idea等词后的表语从句或同位语从句中，谓语形式用动词原形：
My suggestion is that we (should) challenge them for a friendly competition.
I second his motion that we set up a special committee to examine the problem.