<p>The [arrival of] swallows in San Juan Capistrano on the same day each spring [fascinates] scientists, who [continue to] search for [an explanation of the] phenomenon.</p>
<p>Shouldn't "explanation of" be "explanation for"? The answer key says the answer is no error.</p>
<p>[When] L'Enfant suggested [to build] the United States Capitol [at the center of] Washington, D. C., he also [offered] to design a landscaped mall nearby.</p>
<p>The answer is B. Shouldn't "at the center of" be "in the center of"?</p>
<ol>
<li>You do not explain for something.</li>
<li>I got this one wrong, but based of the answer I know “to build” needs to become “building”. I think at and in both work.</li>
</ol>
<p>Does anyone have an explanation for when to use “building” v. “to build”? I do not understand gerund v. infinitive very well.</p>
<p>For gerund vs infinitive, certain verbs take the gerund and certain verbs take the infinitive. I found pretty decent lists on these websites. Suggested takes the gerund and therefore, it must be suggested “building.” </p>
<p>Yes, I petitioned ETS, claiming that “explanation of” was nonstandard in this context and that “explanation for” was the correct choice. Despite the consistent observance of the distinctions in meaning implied by “for” and “of” in every dictionary example I could find (as well as in many other respected publications), ETS denied my petition: they claimed that there was insufficient evidence of the existence of an exception to the general rule that in going from a transitive verb phrase (e.g., “explain the phenomenon”) to a noun-and-prepositional-phrase construction, “of” can be used to connect the object (e.g., “explanation of the phenomenon”).</p>
<p>My guess (without consulting with dictionaries) is that most often:</p>
<p>“explanation of” is used to present something in a more clear and understandable way - as in “explanation of the math concept”; </p>
<p>“explanation for” is used to to give a reason or motivation - as in “explanation for an attack”.</p>
<p>Unfortunately this is not a clear-cut grammatical situation: both “explanation of a mystery” and “explanation for a mystery” are acceptable.</p>
<p>Another example: both sentences
“A theory is an explanation of a phenomenon”
and
“A theory is an explanation for a phenomenon” seem to be correct.</p>
<p>ETS should not have included that question in the test!</p>