Welcome to this little lesson on sentence fragments. There are so many questions on the test that ask about sentence structure or have answer choices that are incorrect because they contain a sentence fragment, which is always incorrect. It is an incomplete sentence, and so it's really useful to know what to watch out for.

所以,首先l let's go through the definition. A sentence fragment does not contain at least one independent clause, so it's not a complete sentence. Most of you probably know that. Well, what do you need to watch out for on the test that might get a little more sophisticated, that might cause you to miss a sentence fragment?

Well, first of all you want to watch out for what are called gerunds. These are these words that end in ing like dancing or running or biking, because they're created from verbs but they are not verbs. So running to the store, that is a sentence fragment. Finishing her experiment before the rest of class, then deciding to leave school early.

Especially when we start to add more words and it gets more complex here. You might think this is fine but then you realize there's no subject. There's no she finished, then decided. Because these are gerunds, they are not acting as verbs here. Now, they can act as verbs, and we have a video, we have other videos, that talk about this as well, too, but you need that helper verb in front of it.

So, for example, she is dancing, if we have that helper verb, then gerunds can act as verbs, because they are creating a progressive tense. But in this case, if you don't have that, finishing her lab experiment or deciding to leave school early, then it is a sentence fragment. The second thing you need to watch out for are the sneaky sentence fragments that seem to be connected to the previous statement but can't grammatically stand alone.

Maybe they're connected by a period, or maybe even by a semicolon when we get a little bit more sophisticated and so she was a wonderful professor, the most wonderful professor. Now, sometimes you might see sentence fragments used this way in less formal writing and novels or a blog post. It creates emphasis, is kind of a unique style choice, but grammatically, if we're being strict about it, it's not correct.

因此，您不会看到在行为上正确使用，因为这一行为非常严格地对学校语法。 So this would not be correct in this case. We can't have the most wonderful professor because that is a subject without a verb. So in this case we have a subject and no verb, and in the cases above here, we don't have a subject, we just have kind of a verb going on with that gerund.

So let's go ahead and see how this plays out on a tough test example. All right, before the 1960 Kennedy-Nixon debates, 首先要电视的辩论，总统候选人依赖于他们履行强大信息和使用细致细微拐点的能力 than on flattering lighting and the best possible camera angle. Oh my gosh, it's a long sentence so you might be like, oh my gosh, and your ear just totally loses track of, what the subject is.

What's the verb? Is there one? So first of all, what I want to make sure that you always do, and this is a good strategy on a test, get rid of those extra clauses. They're not being tested. So if they're being set off with commas they aren't part of the main clause and we can just bracket them off.

And that gives us the main clause to deal with here, which is much shorter. So now if you just read that. Presidential candidates relying more on their ability. Then you're like uh-oh, that is that gerund issue she was just telling me about. So you might be a little bit more on guard for it now after this video then you would otherwise but hopefully you're going to be on guard for it from now on.

So this would need to be relied. We would need that to be in verb form. 所以我们可以扫描，这些是长答案的选择，但如果你知道这个回答的选择中有问题，你可以继续消除它。 So if we said presidential candidates who relied on a powerful message that would also not include the verb because that who changes what's going on with the relied here.

So A and C are out and now we're just looking at B and D. B, relied more on articulating a powerful message and they were using nuanced inflections. D, relied more on their ability to articulate a powerful message and use nuanced inflections. Well, this has cleaner, has good parallel structure, and doesn't use unnecessarily wordy words like B does and they were using, we don't need to say that.

We just need to say they relied and more on their ability to articulate a powerful message and use nuanced inflections. Everything is parallel so it checks out. So D is our answer.