tap

这两个短语意思不同:on tap的意思是“随时供应的,现成的”; 而on the tap则指“在乞讨”“伸手要东西”。例如:

She was always on the tap, borrowing sugar and milk.她借了糖又借牛奶,老是在伸手要东西。

He gave a little tap at the door.

He gave a little tap on the door.

他轻轻叩门。

这组词都有“敲打”的意思。它们的区别是:knock指用手、拳或其他硬的东西用力敲打; rap指用关节、棒等急速地敲,发出刺耳的声音使人们静下来; tap指用手指尖等徐徐地叩或拍。 例如:

We rapped at the door, but there was no answer.我们笃笃地敲门,但无人回答。

The chairman rapped on the table for order.主席敲桌子要求安静。

She tapped her girl to let her sleep.她轻轻拍着女儿让她睡觉。

He tapped his forehead knowingly.他会心地拍拍前额。