既然你累了，就早点休息吧。
jìrán nǐ lèi le ， jiù zǎodiǎn xiūxi ba 。
Since you're tired, go and get some rest.
既然来了，就多玩几天。
jìrán lái le ， jiù duō wán jǐ tiān 。
Now that you're here, stay a few more days.
既然他不想去，我们就别叫他了。
jìrán tā bù xiǎng qù ， wǒmen jiù bié jiào tā le 。
Since he doesn't want to go, let's not ask him.