與現(xiàn)在完成時(shí)連用的時(shí)間狀語(yǔ)如下： 

“for+時(shí)間段 / since（作介詞）+時(shí)間點(diǎn)”；eg.for three years      since three years ago

since（作連詞）+ 從句 （從句中的動(dòng)詞用過(guò)去時(shí)）.因?yàn)閟ince引導(dǎo)的從句表示的是一段時(shí)間,具有延續(xù)性,所以主句中的謂語(yǔ)動(dòng)詞要用延續(xù)性動(dòng)詞.
eg. John has been an English teacher here since he came to our city.