Though I'm tired.I have to finish the work

I'm tired,but I have to finish the work.
although 与 though的用法区别
一、用作连词
表示“虽然”,两者大致同义,可换用,只是 although 比 though 更为正式：
Though [Although] it was raining,we went there.虽然下着雨,但我们还是去了那儿.
二、用作副词
although 一般不用作副词,而 though 可用作副词,且一般放在句末(不放在句首),意为“可是”、“不过”：
It’s hard work; I enjoy it though.工作很辛苦,可是我乐意干.
He is looking fit,though.但他看起来很健康.
三、用于习语
在 as though(好像,仿佛),even though(即使,纵然)等固定短语中不能用 although：
She closed her eyes as though she were tired.她闭上眼,仿佛很疲劳似的.
四、用于倒装
though 引导的让步状语从句可用部分倒装的形式(注意：倒装后位于句首的名词之前不用冠词),但 although 一般不这样用：
Poor though I am,I can afford it.我虽穷,但这东西还是买得起的.
另外注意：
1.although较正式,语气强
Although he was tired,he went on working.
2.although引导的从句放在主句前后均可,有时还可放在句中.
Although many difficulties are still ahead,we are determined to make greater achievements.尽管在前面的道路上还有许多困难,但是,我们决心要取得更大的成就.
He often helps me with my English although he is quite busy.尽管他相当忙,但是还常常帮我学英语.
3.although引导的从句不能与but,however连用,但可与yet,still连用.不能说：Although he was old,but he worked hard.应把but去掉.当然,保留but而去Although也可.
注意:although 的几不:
although不能指假设的情况
although不能作并列连词
although不能作副词,放在词尾