<ol>
<li>The derelict old house [across from] the warehouses and the [even more] decrepit one just beside them [have been placed] on the list of historic landmarks.</li>
</ol>
<p>I thought that have been placed was incorrect, since it is in the present perfect when it should be just in the present, or past. Any thoughts???</p>
<p>[have been placed] is correct because the subject is the “the derelict old house” and “the even more decrepit one.”</p>
<p>To get an idea of whether it’s right, try imagining a similarly structured sentence with a less complex subject:</p>
<p>The houses have been placed on the list of historic landmarks.</p>
<p>^that wasnt my question lol. i was asking about why we use the present perfect in this case.</p>
<p>You COULD use a different tense, but the present perfect isn’t wrong. It’s just a slightly different idea:</p>
<p>“The houses have been placed on the list of historic landmarks” is grammatically correct, so there’s no reason to change it to “the houses were placed on the list of historic landmarks.”</p>
<p>^why isn’t the present perfect wrong in this case?</p>
<p>could you also help me with these two questions??</p>
<p>1st(Barron’s 2400):
Before dinner was served [during] the American Airlines flight from NY to Rome, the brothers [began] to watch “Scary Movie 3” [on] [their] dad’s laptop DVD player.</p>
<p>The book says no error.</p>
<p>2nd(PR):
Thanks to the rapid growth of the internet, the internet service provider [gained] three million subscribers by 1996 and, by 1996, [was gaining] [as many as] a thousand new customers each week.</p>
<p>The book says gained is the error; it should be had gained</p>
<p>If the past perfect is required in the 2nd case, then why isn’t it required in the 1st case…??? this is extremely confusing…</p>
<p>Well, in the sentence in the first post, the verb in question is the only verb in the sentence. Past tense, present tense, and present perfect all work just fine when they’re the only verb in the sentence. They convey different ideas, but they’re all grammatically correct ideas:</p>
<p>“I eat food.” - Present tense</p>
<p>“I ate food.” - Past tense</p>
<p>“I have eaten food.” - Perfect tense</p>
<p>None of those sentences is incorrect because all of the tenses stand alone just fine.</p>
<p>You’re getting hung up on whether to use perfect tense or not in supporting clauses. I’m not sure exactly what the rule is, but I can see why you’d use the correct tenses in the two questions in your last post.</p>
<p>You can use past perfect or past tense in the first one in your last post, but there’s no reason to change it.</p>
<p>“Before dinner, the brothers began to watch the movie.” </p>
<p>“Before dinner, the brothers had begun to watch the movie.”</p>
<p>They both work just as well, so you don’t need to change it.</p>
<p>In the second, you DO need to use the perfect. They key there is “by 1996.” Whenever you want to express that one event was done occurring before another event began, you use the past perfect. For example:</p>
<p>“By the time he arrived, I had eaten.” - Past perfect in the second clause, grammatically correct.</p>
<p>“By the time he arrived, I ate.” - Past tense in the second clause, grammatically incorrect.</p>
<p>I don’t think I’m explaining this very well, but does that make any sense at all?</p>
<p>One important use of present perfect tense is for events that ocurred in the past but without a specific time reference.</p>
<p>Compare:
I killed a banker last week.
I have killed a banker.</p>
<p>ok, so in these two sentences:</p>
<p>the only student to be awarded a community service medal, the senior class president has accumulated more hours of service than any other student when he helped build homes in guatemala last summer</p>
<p>“has accumulated” is inappropriate, since “when he helped build homes in guatemala last summer” is a specific time period in the past?</p>
<p>“Last night was not the first time Charles was exposed to her culinary skills; Christine, a first-rate chef, has cooked for him last week as well”</p>
<p>Here “has cooked” is inappropriate, since “last week” is a specific time in the past. Past simple would be better right? Would past perfect be OK too, since her cooking for him last week happened before “last night”?</p>
<p>@HateBeinSober: In the Scary Movie 3 sentence, don’t the brothers begin watching the movie BEFORE dinner was served? so shouldn’t past perfect be used?</p>
<p>Before dinner was served [during] the American Airlines flight from NY to Rome, the brothers [began] to watch “Scary Movie 3” [on] [their] dad’s laptop DVD player.</p>
<p>The “before” just orders the events: you know that the watching of Scary Movie 3 began before the serving of dinner. Here’s the sentence with the extra part cut out:</p>
<p>Before dinner was served, the brothers began to watch the movie.</p>
<p>Here’s the sentence as it would be if it required past perfect:</p>
<p>By the time dinner was served, the brothers had begun to watch the movie.</p>
<p>The first sentence orders the events; prior to dinner, they began to watch. </p>
<p>The second sentence refers to the specific moment at which dinner began. You look at the exact moment when dinner was served, and then you say that by the time that moment came, they had started watching.</p>
<p>I’m probably not the best person to explain it because I always got by on the test based on what sounded right, but I hope that clears it up.</p>