<p>Can someone explain what is wrong with each? The parantheses surrounds the incorrect parts.</p>
<ol>
<li><p>Underneath the basement floor (lies) the drainpipes that were installed years aago by the original owner of the house.</p></li>
<li><p>Plato and Aristotle taught that the ideal human being is the philosopher - the person of reason who (looked upon) existence with detachment.</p></li>
</ol>
<ol>
<li>drainpipes(plural subject) , so “lie” instead of “lies”</li>
<li>i think it should be “looks upon”, since the sentence states XXX is the philosopher, one who looks upon YYY.</li>
<li>yep “than” is required here because of the idioms “more…than”</li>
</ol>
"drainpipes’ is a plural subject so it requires a plural verb in “lie”</p>
<ol>
<li><p>the philosopher isnt doing an action in the past, looks upon is part of an adjective phrase started by the relative pronoun who</p></li>
<li><p>yea it is than; more, less, greater–they all require a than when used in comparisons.</p></li>
</ol>
<ol>
<li>Underneath the basement floor (lies) the drainpipes that were installed years aago by the original owner of the house.</li>
</ol>
<p>Try changing the sentence structure into…
The drainpipes [that were installed years ago by the original owner of the house] lies underneath the basement floor. If I am correct, the phrase enclosed in brackets is called a restrictive phrase, so you can take that out without mangling the central idea of the sentence.</p>