题目内容：

it is three years since i have seen him
it is three years since i saw him
有什么不同.表达效果还是意思什么的?

优质解答

It is three years since I have seen him我已经三年没见过他了.（见他这一动作持续三年都没有发生过,直到现在.）since 后是现在完成时It is three years since I saw him自从我见到他以来已经三年了.（从过去见到他...