yet表“尚未”.He has not yet finished his homework.
yet表“尚未”時(shí),不總是出現(xiàn)在完成時(shí)中.例如The real challenge is yet to come.(真正的挑戰(zhàn)還沒有到來).這句話暗含的意思是“真正的挑戰(zhàn)”總會(huì)到來,只是時(shí)間問題.
yet另一個(gè)意思是“但是”,表示比but稍弱的轉(zhuǎn)折.
just表“剛剛”.He has just finished his homework.
但是大多數(shù)時(shí)候,just使用一般過去式就完全足夠了,比如He just finished his homework.
just作副詞還有“僅僅,只要”的意思；形容詞表示“公正的”.
before大多數(shù)時(shí)候出現(xiàn)在將來時(shí),一般現(xiàn)在時(shí),一般過去式和過去完成時(shí).
He will finish his homework before 8.00.
If he finishes his homework before 8.00,he will be rewarded by his mom.
He finished his homework before 8.00.
He had finished his homework before his mom went mad at him.
ever表示“從來；永遠(yuǎn)”.一般以這種形式出現(xiàn)在一般/過去完成時(shí)中：
That is the best show he has ever seen.
其他情況下,ever可以用在各種時(shí)態(tài)：
He will never ever trust her again.(強(qiáng)調(diào)ever,類似于肯定形式的never)
He thinks himself to be ever correct.(代替always)