求英语复合句时态公式!比如When后面用什么时态?Since后面用什么时态?While后用什么时态?If后用什么时态?

/>以下例句:I was sleeping when he was wathcing TV。（过去进行式)= When he was wathcing TV,I was sleeping。Every day I read newspaper when I eat breakfast。（现在式）= Every day when I eat brakfast,I usually read newspaper。What do you have to do when you go to school?(现在or未来式皆可)(1)since + 过去一个时间点 (具体的年、月、日期、钟点)。I have been here since 2002。(2)since +一段时间+ agoI have been here since six months ago。(3)since +从句 I'm very sad since you left。(4)It is +一段时间+ since从句It is six months since I came here。>while所接子句中的动词是进行式or单纯式,但需要是有持续性的动作或状态例:While there is life,there is hope。(有生命就有希望)>对现在、将来不确实事情的推测or对现在的事实相反的假设or与过去事实相反的假设皆可;if 后面所连接的子句,可放在句首也可放在句中,但若是放在句首,则和其后子句间要用逗号分开。例:I won't go out if you come here tomorrow。=If you come here tomorrow,I won't go out。