我们先来看一道考题：
Only in this way __________ able to finish the work in time.
A. can you be B. are you C. you can be D. you are
此题应选 B。容易误选D。至于A，C，这比较容易排除，因为情态动词 can 不能与 be able to用在同一谓语中。本题之所以要选B而不选D，主要是因为句首用了only in this way 的缘故，按照英语语法规则：only+状语位于句首，句子通常要用倒装语序(部分倒装用一般疑问句形式)：
1. only+副词位于句首：
Only then did I realize that I was wrong. 只是到了那时我才意识到是我错了。
Only by shouting was he able to make himself heard. 他只有叫喊才能让别人听到他。
The pilot reassured the passengers. Only then did I realize how dangerous the situation had been. 飞机驾驶员要乘客们放心，这时我才明白刚才的情况有多危险。
2. only+介词短语位于句首：
Only by working hard can you succeed. 只有努力工作你才能成功。
