含有否定意义的副词或连词如hardly,never,not,not only,little等被前置时用部分倒装。例 词组hardly...when和no sooner...than都表示“刚刚…就”的意思。为了强调，这类句子也常常用倒装语序。例如：I had no sooner got there than it started raining heavily.变成：No sooner had I got there than it started raining heavily. 如果还是不明白的话我建议你去买本语法书来看，里面说的会更全面些…

no sooner than ...... equals to "as soon as..." eg:No sooner was the frost off the ground than the work began. 地上的霜一消散，人们就开始工作了. hardly when Hardly had the thief seen the policeman when he ran away. = Scarcely had the thief seen the policeman before he ran away. <before=when> =No sooner had the thief seen the policeman than he ran away. =As soon as the thief saw the policeman, he ran away. =Upon seeing the policeman, the thief ran away. <upon=on> <as soon as=the instant (when)=the moment (that)=immediately after=directly after=right after>

never, hardly, not only, nor, little, seldom, nowhere, not until, hardly…when, no sooner…than, by no means等表示否定或半否定意义的副词或词组开头的句子中，该句主谓要倒装。