风唱梵音你好.【表示与现在相反】从句：主语+过去时 　　主句：主语+should/would/could/might+do eg.If I were you,I would take an umbrella.如果我是你,我会带把伞.（事实：我不是你） 2.If I knew his telephone...这个我找了，关键是从语境中如何分析。看时态吖。（说实话 我没明白你的追问= =）举个例子！百科里不是有咩＝ ＝