Invert The Subject And Verb With Comparisons

An inverted subject and verb may also occur after a comparison. The inversion of a subject and verb after a comparison is optional, rather than required, and it is a rather formal structure. There have been a number of inverted comparisons on recent TOEFL tests, so you should be familiar with this structure.

My sister spends more hours in the office than John.
My sister spends more hours in the office than John does.
My sister spends more hours in the office than does John.

All three of these examples contain the comparison more ... than, and all three are correct in English. It is possible to have the noun John alone, as in the first example; it is possible that the comparison is followed by the subject and verb John does, as in the second example; it is also possible that the comparison is followed by the inverted subject and verb does John, as in the third example.

The following example shows how this sentence pattern could be tested in structure questions on the TOEFL test:

Example from the Paper and Computer TOEFL® Tests
The results of the current experiment appear to be more consistent than _____ the results of any previous tests.
(A) them
(B) were
(C) they were
(D) were they

In this example, you should notice the comparison more consistent than,
and you should also understand that the results of the current experiment is being compared with the results of any previous tests. Because the results of any previous tests is the subject, only a verb is needed; the best answer to this question is therefore answer (B). We know that it is possible for a subject and a verb to be inverted after a comparison, and in this case the subject the results of any previous tests comes after the verb were.