1) 有些动词用一般现在时代替完成时,如hear, tell, learn, write , understand, forget, know, find , say, remember等。例如:
I hear (= have heard) he will go to London. 我听说了他将去伦敦。
I forget (=have forgotten) how old he is. 我忘了他多大了。
2) 用句型 " It is … since…"代替"It has been … since …".例如:
It is (= has been) five years since we last met. 从我们上次见面以来,五年过去了。