第1个回答 2007-09-17
only then ,是过一小会儿的意思，一般用在句首，引导倒装句。
例句Only then did he realize the importance of English．
解析：在句首的only如果后面跟了副词、介词短语或从句等状语，则主句用倒装结构。如only后跟的是主语，就不用倒装结构了。
再比如
Only when the war was over in 1918 was he able to get back to work．(倒装句）
Only five men were hurt in the accident．（不倒装）
第2个回答 2007-09-17
only then ,是过一小会儿，then 指然后，与at first ,next ,then ,(then和next可调换），finally,表示时间顺序。
只有在那时候他才意识到英语的重要性。
误：Only then he realized the importance of English．
正：Only then did he realize the importance of English．
解析：
在句首的only如果后面跟了副词、介词短语或从句等状语，则主句用倒装结构。如only后跟的是主语，就不用倒装结构了。例如：
Only when the war was over in 1918 was he able to get back to work．
Only in this way can you learn English well．
Only after a bitter struggle was the aim achieved．
Only the teachers are allowed to use the room．（不倒装）
Only five men were hurt in the accident．（不倒装）
注意，only和所修饰的状语如果不在句首，则不倒装。
如：
The boy was helped out only when his father arrived in a hurry．
第3个回答 2007-09-17
only then仅仅在那时only引导状语,句子要实行半倒装
例如:
only then did I realised that you are very important to me.
第4个回答 2007-09-17
Only then did he realize that he had made a mistake.只有到那个时候，他才认识到自己犯了个错误。