SAT语法知识点很多，考生非常容易在备考的时候因为过于关注一些热点的知识点而忽略一些不常见的知识点。下面天道小编就为大家整理了这样的三个知识点，虽然不是每一次考试都会见到，但是对大家的成绩还是有很大的影响的。我们来看看详细内容吧。

　　The Little Three

　　In addition to the Big Five, you’ll likely see a question once in a while that dealswith one of these three concepts:

　　Conjunctions

　　Fragments

　　Coordination and subordination

　　We call these the Little Three, and below we explain them all.

　　1. Conjunctions

　　Conjunctions are connecting words such as and, but, that, and or. They help linktwo parts of a sentence together. Suppose you have two sentences:

　　Abigail jumped off her horse. She then dove into a pool of deep water.

　　A conjunction such as and enables you to connect the two halves of the sentence:

　　Abigail jumped off her horse and into a pool of deep water.

　　Improving Sentences questions test you on conjunctions by including sentencesin which the conjunction makes the sentence illogical or clunky.

　　Nick wrote a novel and it depicts the life of a somewhat inspiring record store clerk.

　　(A) and it depicts

　　(B) being the depiction of

　　(C) it depicts

　　(D) that depicts

　　(E) and depicting in it

　　The right answer is D. In this sentence, the conjunction that expresses the function of the novel more smoothly than the clunky phrase and it does.

　　2. Fragments

　　Fragments are almost the opposite of run-on sentences. Run-on sentences have clauses squashed together and joined incorrectly. Fragments have no independent clause and therefore are incomplete sentences.

　　The hunchback vice principal growling at students in the main office.

　　(A) The hunchback vice principal growling

　　(B) The hunchback vice principal having growled

　　(C) Growling, the hunchback vice principal

　　(D) It is the hunchback vice-principal

　　(E) The hunchback vice principal growls

　　In this sentence, the clause lacks a proper verb for the subject (the hunchbackvice principal). The sentence would be complete if it read, The hunchback viceprincipal growling at terrified students was notorious for his brutal tactics. Notice though that the answer choices don’t fix the fragment that way. Instead,the correct answer, E, takes away the problem of expectation altogether. Whenyou read The hunchback vice principal growls at terrified students, you don’t expect the sentence to continue. He growls and that’s the end of the story.

　　3. Coordination and Subordination

　　Bad coordination happens in gym class when you trip over your own feet or crash into someone else on the field. Bad coordination in a sentence happens when two clauses are joined together with a word that makes their relationshipconfusing.

　　John made T-shirts for the swim team, but he designed the logos himself.

　　(A) but he designed the logos himself

　　(B) however, he designed the logos himself

　　(C) and he designed the logos himself

　　(D) since he designed the logos himself

　　(E) and yet, he designed the logos himself

　　The sentences makes it clear that John creates his own T-shirts. He also designslogos for the T-shirts. So should the word but express the relationship betweenthese two activities? No, because the two activities are closely related. The wordbut would make sense only if the sentence said something like John made T-shirts, but other than that he sat around playing video games all day. The word but suggests a contrast, a change in the direction of the sentence. If youget to the middle of a sentence and it takes an unexpected turn, look for a coordination error.

　　In this question, you can eliminate B because the word however is also a bad choice when joining these two clauses. It expresses the same kind of contrasting relationship as does the word but. You can eliminate E for the samereason. Answer D isn’t quite as bad as B and E, but John made T-shirts for theswim team, since he designed the logos himself doesn’t make that much sense.John doesn’t make T-shirts because he designs the logos, he makes T-shirts and designs the logos, which is exactly what C says. Bingo.

　　We thought it would be helpful to put together a list of conjunctions and split them up based on whether they suggest contrast or no contrast. Contrast conjunction words like but require the meaning of the sentence to change direction. For example, “I would go to school, but I don’t feel well.” Noncontrast

　　conjunction words like and keep the sentence flowing in the same direction. Forexample, “After school I will practice piano and eat a snack.”

　　Here’s a chart to help you learn the most important contrast and non contrast conjunction words.

　　Noncontrast Conjunctions：and　　because　　since　　so　　hus　　therefore

　　Contrast Conjunctions：but　　though　　although　　while　　trather　　instead　　unless　　despite　　however　　nevertheless　　notwithstanding

　　Subordination problems happen when there are two subordinate clauses and nomain clause. You don’t need to know what that jargon means. Instead, you justneed to know subordination problems tend to occur when sentences contain more than one of the conjunction words listed above. If you see one clause thatstarts with although, because, if, since, or so that, and then another clause thatstarts with one of these words, you’ll hear the subordination problem loud andclear:

　　Because Teddy thought his first date with Maria went well, so that he called her every day for the next week.

　　(A) so that he called her every day for the next week

　　(B) although he called her every day for the next week

　　(C) because he called her every day for the next week

　　(D) he called her every day for the next week

　　(E)and he called her every day for the next week

　　You don’t need to know that this sentence is an example of bad subordination.Just notice that the two parts of the sentence don’t go together. Why don’t theyfit together? Because there’s something strange about the middle of the sentence. You hit the comma, and then the sentence takes an unexpected turn.

　　The first part of the sentence sets you up: Since Teddy thought his first date with Maria went well, you expect something along the lines of he invited her outagain or he kissed her on her front porch, right? Instead, you get the phrase sothat. That just sounds incorrect and doesn’t make a lot of sense.

　　Knowing the sentence contains an error allows you to eliminate A. In B, the word although gives you exactly the same sort of problem that plagues the original sentence. Same with C, because. He thought the date went well because he called her every day the next week? No. That doesn’t make sense.In E, the word and doesn’t go with the although that starts the sentence. PlugD back into the sentence to make sure it fits: Because Teddy thought his first date with Maria went well, he called her every day for the next week. Lookin’ good.

　　As we emphasized a few times already, relying on your ear and on what “soundsright” is dangerous on the SAT. The SAT wants you to trust your ear and go with what you think might sound right in converSATion or casual English. Remember that the SAT is anything but casual and that Improving Sentences questions test standard written English, not the same English you speak with friends or family. That makes learning the rules and familiarizing yourself withthese words all the more important.