我认为你这次没错。
　　I believe that he is sure to come．---I don't believe that he is sute to come．
　　我相信他肯定不会来。
　　2. when，while，till，until，before，after，
　　as soon as, as
　　when，while, till until，befOre，after，as soon as，as等连词用事引导时间状语从句。例如：
　　I was listening to musicwhenmy father cameback home．
　　我爸爸回家时，我正在听音乐。
　　She was dancmg while her mother was playin the piano．
　　她妈妈在弹钢琴时，她在跳舞。
　　All my friends had arrived before I came.
　　在我来之前，我所有的朋友都到了。
　　He listened to music as he was walking．
　　他一边走一边听音乐。
　　 3.because，as，since
　　because，as，since用来引导原因状语从句。例如：
　　I didn't go to work last week because I was badly ill.
　　我上周没上班是因为我得了重病。
　　As she is thin，she can't carry the box．
　　由于身体单薄，她扛不动这个箱子。
　　Since everyone has come, let's begin our meeting.
　　既然大家都到齐了，我们就开会吧。
　　注意
　　because表原因，直接说明因果关系，能回答why的提问；for用来解释出现某种结果的理由，只能放在句尾；since表原因，比because语气稍弱，不如beeause正式，往往表示间接的或附带的原因，多用于句首；as表原因，其语气比because和since都弱，as多用于日常生活会话中，它引导的从句往往放在主句之前。例如：
　　Because he was ill，he didn't go to school yesterday．由于生病，他昨天没有去上学。
　　It's getting cold，for winter has come．
　　天气变冷了，因为冬天来临了。
　　Since it's fine today，let's So picnicing．
　　 （既然）今天天气好，咱们去野餐吧。
　　As he was ill，we didn't tell him about．
　　由于他病了，我们就没把这件事告诉他.
　　 4. if, unless，even if(though)，though
　　 (although)
　　if,unless，even if(though)，though (although)引导条件或让步状语从句。例如：
　　You mustn't move someone if he is badly hurt.
　　如果一个人受了重伤，你一定不要去挪动他。
　　you won't pass the exam unless you work harder.
　　如果你不更加努力学习，你考试就不会过关。
　　We are still good friends though we quarrelled.
　　尽管我们吵厂架，我们仍然是好朋友。
　　They will keep on practising even if (though)it is rainy.
　　即使天下雨他们也将继续训练。
　　5. so...that...
　　so…that…表示“如此……以至于……”，用来引导结果状语从句。例如：
　　I was so tired that I couldn't move a bit.
　　我累得走不动了。
　　We practised so hard that we beat the boy team.
　　我们训练得很刻苦，所以打败了男子队。
　　 注意
　　注意so... that...与such...that...too...to…，enough to ...的互换。
　　She is so sick that she can't go out．
　　She is such a sick person that she can't go out．
　　She is too sick to go out．
　　He works so hard that he gets the first place in his class．
　　He works hard enough to get the first place in his class．liuxuepaper.com