as / though引导让步状语从句时，一般须用部分倒装。如：
Old as / though he is, he works like a young man.
Hard as / though he was working, he didn’t pass the exam.
Try again as / though he will, he can’t succeed.
as / though引起的倒装分三种情况：表语、动词原形及状语的倒装。
一般直接将表语提前到句首，若表语是带不定冠词a / an的单数可数名词，倒装后，不定冠词a / an须被省略。如：
Fine as / though he looks, he is ill with some serious diseases.
Child as / though he is, he knows much about the society.
A. 动词前面带有情态动词may, might, will, would, can, could等时，只将行为动词提到句首，而这些情态动词保留在原处。
Swim as / though he can, he can’t swim so far.
Run as / though he did, he didn’t run fast enough to catch the bus.
In the classroom as / though he stays, he doesn’t read his texts.
Carefully as / though he worked, he made some mistakes.