英语直接引语变间接引语 什么情况下只是去掉引号

你所提的问题只能是一种特例.
1.如果引号外面“某某人说”用的是现在时态,则间接引语的时态也不要变化；直接引语是陈述句,则间接引语的单词顺序也不要变化；引导词 that 又可以省略,得到的句子就符合你的问题.例句：
直接引语：He always says,"Nothing in the world is difficult if you put your heart into it." （他总是说,“世上无难事,只怕有心人.”）
间接引语：He always says nothing in the world is difficult if you put your heart into it.
2.引号外面“某某人说”不管是用现在时还是过去时,直接引语为陈述句,而且直接引语是一个科学真理或客观事实,则改为间接引语时,时态不用变化,引导词 that 也可省略.例如：
直接引语：The scientist said,"The earth moves around the sun."
间接引语：The scientist said the earth moves around the sun.
3.如果直接引语是在当地、当天转述的,有时也可以不改变时态.例如：
直接引语：She said,"Tom will go to London next week."
间接引语：She said Tom will go to London next week.
（但这句话更多情况下是这样改为间接引语的：She said (that) Tom would go to London the next week.）
我只能说出这些.