since和before的用法有什么区别呢

1个回答

假设过去某一时点为A,现在时点为B,则since表示从A到B的时间内,before表示A点之前
用法上since一般接have done sth,before一般接 did sth
相应翻译为从A时点后,一直.和在A时点前,曾经.
如I haven't seen him since Christmas.与I saw him before Christmas
翻译：自从圣诞节后我就没见过他及我在圣诞节前见过他