我明白了.比如说：
1 Though he tried,he couldn't finish his work on time.-----------
你可以改写成：Try as / though / that he did,couldn't finish his work on time.
2 Though he will try,he will not be able to finish the work on time.------------
你可以改写成：Try as he will,he will not be able to finish the work on time.
(其实呢,非常简单,就是把从句中谓语部分的主动词提前,助动词放在后面就成了.)