Bob isjacket is dirtier than John is jacket.
问题描述：
Bob isjacket is dirtier than John is jacket.
答
正确的应该是这么写的吧：
Bob's jacket is dirtier than John's jacket.
Bob的夹克衫比John的要脏的多.
（别把所有格当成be动词的格式了.）