<p>Experts agree that permanently modifying eating and exercise habits rather than merely dieting for brief periods (C) ARE THE KEY to controlling weight.</p>
<p>All other parts except for the capitalized are okay. But I can't get the trick with the key.
Can somebody tell me which rule is applied here?</p>
<p>should be plural, keys, since its referring to the compound subject, modifying eating and exercise habits.</p>
<p>Thanks a lot!</p>
<p>What? The subject is “modifying,” and the verb should be “is.”</p>
<p>“Eating” and “exercise habits” are objects of the gerund “modifying,” but neither of them is a subject of the verb in that clause.</p>
<p>If you strip out all the extraneous elements of this clause, it says that MODIFYING IS the key.</p>
<p>Yep, Sikorsky is correct. It should be changed to (C) IS the key</p>
<p>So, the verb’s there for the “permanently modifying”?
Is that what you say?</p>
<p>I mean that the verb must agree with its subject, which is “modifying.” Since “modifying” is singular, the verb must be singular.</p>
<p>Oh wow, i read it too quickly and just figured that eating and exercise habits were the subjects when they are objects… bleh. i have trouble sometimes figuring out these obscure subjects like modifying… tips on that guys?</p>