since if的用法总结

回答
爱扬教育

2022-03-13

since +过去一个时间点 (如具体的年、月、日期、钟点、1980, last month, half past six);
since +一段时间+ ago I have been here since five months ago;
since +从句;
It is +一段时间+ since从句。

扩展资料

  if作为连词,引导条件状语从句,表示“假如”、“如果”等意思。在复合句中如果主句用将来时,则if引导的状语从句用一般现在时。

since if的用法总结

  if可以引导让步状语从句,表示“即使是”、“虽说”之意。

  if作为连词可以引导宾语从句,和whether意思相同。

  You can come with us if you want to.

  如果你愿意可以跟我们一起来。

  Put your hand up if you need more paper.

  若有人还要纸,请举手。

  Only time will tell if the treatment has been successful.

  只有时间才能证明这种疗法是否成功。

  She's a changed woman since she got that job.

  她自从得到了那份工作,变得判若两人。

  She's been using since she was 13.

  她从13岁起就吸毒。

  His quality of life has improved dramatically since the operation.

  手术后他的生活质量大大改善了。