I went through the MGMAT SC guide but am still unclear on when the second verb in a comparison is understood and when it is not.

For example, the second verb (am) is understood in the following sentence -

John is taller than I (am).

However, the second verb (do) is explicitly stated (and not understood) in the following sentence -

Australian wines taste better than French wines do.

Could you please clarify?

Thanks,
Mandy

I would greatly appreciate any help you can give me with this question.

Thanks,
Mandy

Mandy,

Though your example is an exception to the "rule," the general principle to follow is that the second verb must be stated when ambiguity would result from its absence. For example, the sentence "Mandy likes Nick Lachey more than her friends" is ambiguous. Does Mandy like Nick Lachey more than she likes her friends, or does Mandy like Nick Lachey more than her friends like Nick Lachey? To clarify, it is necessary to include the second verb. In this case, the second interpretation is more likely than the first, so the proper sentence would be ""Mandy likes Nick Lachey more than her friends do."

As for your specific examples, neither is inherently ambiguous; thus, the inclusion of the second verb is more a question of style than of substance. In my opinion, either of those examples could include or exclude the second verb without altering the intended meaning of each sentence. Thus, on the GMAT, there would have to be additional, provable grammatical errors in those sentences in order to eliminate them as potential answer choices.

Hope that helps!
-dan

Thanks much for the super explanation Dan! You guys are the best!

Thanks,
Mandy