1.“进行时+when+一般时”表示“正在……,就在这时” 孩子们正要离开学校,这时他们看见了一辆卡车。 误The children left school when they saw a truck. 正The children were leaving school when they saw a truck. 2.while不能用于含有表示一时性动作的动词的句子 当我讲话的时候请安静。 误Please be quiet while I speak. 正Please be quiet while I am speaking. 3.表示一时性动作的动词,如:finish, return, start, leave, come, reach, go要用其否定式与till/until连用 我恐怕要在他来之前才能完成工作。 误I'm afraid I can finish the work when he comes. 正I'm afraid I can't finish the work until/till he comes. 表持续性动作的动词,如:stay, wait要用其肯定形式与till/until连用。 我呆在那里直到他回来。 误I stayed there when he arrived. 正I stayed there until/till he arrived. 4.because所引导的从句可放在句首;for连接的分句不能放在句首 他不害怕,因为他很勇敢。 误For he was very brave, he felt no fear. 正He felt no fear, for he was very brave. because表示直接的原因;for表示推断的原因。 一定是早晨了,鸟在叫呢。 |
|