If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Main content

SAT

Unit 11: Lesson 3

Writing: Grammar

Sentence fragments | Quick guide

What are sentence fragments?

What's on the test?

Tips and strategies

Your turn!

Want to join the conversation?

  • duskpin sapling style avatar for user Amulya M
    I'm a bit confused. Non-essential phrases (the stuff bound by commas) can be removed and the sentence should still make sense right?

    Then why is it that in the second practice question- for which the answer is "While they have been largely replaced by Arabic numerals, Roman numerals are still used in a few contexts because it is sometimes useful to have distinct numerals for distinct purposes, like when numbering the quadrants of a graph."- when we remove the words bound by commas ("Roman...purposes") the sentence doesn't make sense?
    Is it that when a conjunction is added in a phrase bound by commas it no longer behaves like a nonessential phrase? Or do we consider the words on both sides of the conjunction as two separate phrases?

    Also, I don't completely understand these terms- phrase, clause and non-essential phrase. It'd be great if someone could explain them using examples.
    (4 votes)
    Default Khan Academy avatar avatar for user
    • piceratops ultimate style avatar for user Hecretary Bird
      What you have between the commas in that sentence, "Roman numerals are still used in a few contexts because it is sometimes useful to have distinct numerals for distinct purposes" functions as an entire sentence by itself. It's made up of an independent clause ("Roman numerals are still used in a few contexts") and a dependent clause ("because it is sometimes useful to have distinct numerals for distinct purposes").
      Clauses are bits of words with a subject and a verb in them. Take "Roman numerals" and "are used" in the first clause, and "it" and "is" in the second clause. This is the key difference between them and phrases. A clause, even a dependent one, will always have a subject and a verb, while a phrase will never have both a subject and a verb in it.
      The way I've learned it is that a phrase is just a group of words acting together to express one idea, like in "around the world" or "slurping greedily".
      Now, nonessential phrases are phrases that can be removed from the sentence, like you said. The main way we signify that a phrase is nonessential is with the commas surrounding it. In the sentence: "Usnavi, a very hairy man, was fearsome to behold", knowing that Usnavi is hairy isn't essential to getting at the main meaning of the sentence, which is that he's fearsome. For the most part, you can tell if a phrase is nonessential or not just from its meaning and how it relates to the meaning of the sentence.
      There are tricky situations, though. Take the sentence: "The person cutting Usnavi's hair was even hairier than he was." Here, we don't put commas around "cutting Usnavi's hair" because it's essential information to understanding who the man is. It's a bit confusing.
      So a phrase is a group of words that work together to achieve a greater meaning, a clause is a group of words with a subject and a verb, and a nonessential phrase is a phrase is separated from the rest of the sentence by commas because without it, the sentence is still specific and has a meaning that makes sense. You can have nonessential clauses as well, and just plain words too, which you also have to put commas around.
      (13 votes)
  • aqualine sapling style avatar for user Dumb Cat
    Why is "He tried to lose weight" a dependent clause?
    (1 vote)
    Default Khan Academy avatar avatar for user
    • piceratops ultimate style avatar for user Hecretary Bird
      It shouldn't be, did you see it on this article? "He tried to lose weight" is a complete thought that stands on its own, so its an independent clause. If you add a subordinating conjunction to the front like "because he tried to lose weight", that wouldn't be a complete thought by itself and so would be a dependent clause.
      (3 votes)
  • blobby green style avatar for user dewantorotriatmojo
    Incorrect : "Periodical" is an umbrella term used to refer to various publications released on a regular schedule. Including magazines, academic journals, and yearbooks.

    Can I make it this way?
    "Periodical" is an umbrella term used to refer to various publications released on a regular schedule including: magazines, academic journals, and yearbooks.
    (2 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user hawaii2484
    Regarding the example used in the Sentence Fragments exercise, why are the words "that are" omitted between "publications" and "released"?

    "Periodical" is an umbrella term used to refer to various publications released on a regular schedule, including magazines, academic journals, and yearbooks.
    (1 vote)
    Default Khan Academy avatar avatar for user
    • male robot hal style avatar for user Yash
      The sentence is grammatically correct whether it's written as "Periodical" is an umbrella term used to refer to various publications released on a regular schedule, including magazines, academic journals, and yearbooks. or "Periodical" is an umbrella term that is used to refer to various publications that are released on a regular schedule, including magazines, academic journals, and yearbooks.

      The first option is just shorter, so it's "correct"
      (3 votes)
  • blobby green style avatar for user 4/Chacin/Jose
    What could happen if the crocodile does not reposition itself or refresh its brain, what changes can it have.
    (2 votes)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user Shania Chenier
    how can i lean more about this
    (1 vote)
    Default Khan Academy avatar avatar for user
  • male robot johnny style avatar for user Bakytzhan
    "Roman numerals are still used in a few contexts. Because it is sometimes useful to have distinct numerals for distinct purposes, like when numbering the quadrants of a graph."

    Why text after "because" is dependent clause?
    (1 vote)
    Default Khan Academy avatar avatar for user
    • piceratops ultimate style avatar for user Hecretary Bird
      "Because" and the words after it form a dependent clause, because that bit cannot stand on its own without some help from another clause. "Because" and the words after it serve to answer the question "why are roman numerals still used in a few contexts", and because you need that information for the dependent clause to have relevance it is a dependent clause.
      When looking out for dependent clauses, you can often start by trying to find subordinating conjunctions such as "because", "after", "although", etc.
      (1 vote)
  • blobby green style avatar for user jay.hayes1
    how do you properly know when it's a good time to use commas and semicolons ?
    (1 vote)
    Default Khan Academy avatar avatar for user
  • blobby green style avatar for user helen.zhang
    “Limestone is considered a sedimentary rock since it is formed out of independent particles that have cemented over time.”

    Should you put a comma before ‘since’ so it will be like “Limestone is considered a sedimentary rock, since it is formed out of independent particles that have cemented over time.”? Is that also grammatically correct?
    (1 vote)
    Default Khan Academy avatar avatar for user
    • female robot amelia style avatar for user Johanna
      Actually, no, you don't need a comma. This sentence is made out of the independent clause "Limestone is considered a sedimentary rock" and the dependent clause "since it is formed out of independent particles that have cemented over time.”

      You do need a comma when the dependent clause comes before the independent one. For example, you would need a comma if the sentence were: "Since it is formed out of independent particles that have cemented over time, limestone is a sedimentary rock." However, the sentence you provided has the independent clause come first, so there's no comma.

      Did that help?
      (1 vote)
  • duskpin ultimate style avatar for user Angelica Lappay
    Why does this sentence, "Limestone is considered a sedimentary rock since it is formed out of independent particles that have cemented over time" not use a comma before the subordinating conjunction "since"?
    (0 votes)
    Default Khan Academy avatar avatar for user
    • piceratops ultimate style avatar for user Hecretary Bird
      You're correct that you usually do need a comma separating two clauses, but not in every case. If you have an independent clause with a dependent clause after it, like in the example you provided, you don't need to have a comma to separate them. If it's the other way around, like in: "Since it is formed out of independent particles that have cemented over time, limestone is considered a sedimentary rock", then you would need a comma to separate the clauses.
      This won't show up on the SAT, but in some cases the sentence can be ambiguous without the comma, so its better that you put it in. For example, in: "Usnavi didn't call his best friend because he was tired", you could think of the situation as Usnavi not calling his friend because he was too tired to, or alternatively as Usnavi calling his friend, but for a reason other than him being tired and wanting some relaxing chit-chat. Putting a comma would solidify that you meant the first meaning instead of the second.
      (1 vote)