Preverb
句首助动词, 前动词(即移至句子第一个位置上的助动词)
🗣️ 情景例句
We are looking forward to our holidays.
我们盼望着假期的到来。
Is this a local broadcast?
这是不是当地的广播？
When the balloon was over the station, the pilot saw one of the men taking photographs.
当气球飞临基地上空时，飞行员看见有一个人在拍照。