倒装分为全倒装和半倒装，正常的顺序是主语+谓语+宾语等。
半倒装，就是把助动词/情态动词/be动词。提到主语前。、
否定意义的词位于句首时需要用半倒装， 如 no, not, hardly, barely, little等等如： Hardly can I understand what you said.
only加副词或介词短语或状语从句，且位于句首时需要这种半倒装，如，Only in this way, can I get close to you.
又如：
Only then did she realize how much damage had been caused.
Not until I came home last night did Mom go to bed.
Little did Rose care about her own safety.
By no means is the teacher satisfied with my progress.
希望我能帮助你解疑释惑。