twice没有比较级和最高级。

adv. 两次两倍She's backpedalled twice already.

她已经两次改变主意了。

I go swimming twice a week.

我每星期游泳两次。

The villa is cleaned twice a week.

这栋别墅一周打扫两次。

Cats sleep twice as much as people.

猫睡觉的时间比人长一倍。

I visited once or twice.

我参观过一两次。