并列连词

If it doesn't rain,we'll go to the park.

如果不下雨,我们就去公园。

Though I was tired, I still worked hard.

虽然我很累,可是我仍然努力地工作。

1.if:如果(引导条件从句)

You can pass the exam if you study hard.

如果你努力学习,你会及格的。

2.though,although:虽然(引导让步状语从句)和原因状语从句一样,如果用了though,although (虽然)就不能再用but(但是)。

Although(Though) I live near the sea, I'm not a good swimmer.

=I live near the sea,but I'm not a good swimmer.

虽然我住在海边,可是我游泳并不好。

注意

注意时态一致,和时间状语从句一样。主句是将来时之时,从句要用一般现在时。