1) 有些动词用一般现在时代替完成时: hear, tell, learn, write , understand, forget, know, find , say, remember. I hear (= have heard) hesince;adv.后来;conj.既然,因为,自从;prep.自从;参考例句:He's been working in a bank since leaving school.自从毕业后,他就一直在一家银行工作。 I have known him ever since I was a child.我自孩提时代起就已经认识他了。