Praxis Core · Writing (5723) Selected Response
Praxis Core: Sentence Correction and Mechanics Concepts
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Overview
This chapter is about choosing the best way to write a sentence. You will fix run-ons and fragments, correct comma mistakes, make lists parallel, and move modifiers so they describe the right word. The best answer is grammatically correct, clear, and not wordy.
A complete sentence needs a subject and a verb and must express a full thought. A fragment is missing one of these. A run-on joins two complete sentences without the right punctuation, and a comma splice joins them with only a comma.
Parallel structure means items in a list or comparison use the same grammatical form. A modifier should sit right next to the word it describes; when it does not, the sentence can say something silly. Among correct choices, the shorter one that keeps the full meaning is usually best.
Key concepts
Run-on and comma splice
A run-on joins two complete sentences with no punctuation. A comma splice joins them with only a comma. Fix with a period, a semicolon, or a comma plus a joining word like and, but, or so.
Memory tipTwo full sentences need a strong break: . or ; or , + and/but/so.
Sentence fragment
A group of words punctuated as a sentence but missing a subject, a verb, or a complete thought, such as "Because the bus was late."
Memory tipIf it leaves you asking "and then what?", it is a fragment.
Parallel structure
Items in a list or comparison should share the same form: "reading, writing, and speaking," not "reading, writing, and to speak."
Memory tipLists should match like a set of dishes.
Misplaced or dangling modifier
A describing phrase must be next to the word it describes. "Walking to school, the rain started" wrongly says the rain was walking.
Memory tipAsk who is doing the -ing action; that person must come right after the comma.
Semicolon and colon
A semicolon joins two closely related complete sentences. A colon comes after a complete sentence to introduce a list, an explanation, or an example.
Memory tipSemicolon between two sentences: a full sentence on both sides. Colon: a full sentence before it.
Concise wording
Avoid repeating the same idea or using extra words, as in "past history" or "due to the fact that." The shortest correct, clear choice is usually best.
Memory tipIf two words say the same thing, cut one.
Often tested
- Two complete sentences need a period, a semicolon, or a comma plus a conjunction (a colon also works when the second explains the first).
- Items in a list should have the same grammatical form.
- The best answer is correct, clear, and not wordy.
- A modifier must sit next to the word it describes.
- A comma alone cannot join two complete sentences.
Easy to confuse: Fragment vs. run-on
| Error | Problem | Fix |
|---|---|---|
| Fragment | Not a complete thought | Add the missing subject, verb, or clause |
| Run-on / comma splice | Two complete thoughts joined wrongly | Period, semicolon, or comma + conjunction |
3 sample questions
Verified practice questions from this unit.
Question 1. Choose the best version of the part of the sentence in square brackets. The first choice repeats the original wording. The students finished the experiment[, they wrote] their reports the next day.
- ① , they wrote
- ② they wrote
- ③ ; they wrote
- ④ , and writing
- ⑤ , while they wrote
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Answer: ③ ; they wrote
Key point: Two complete sentences cannot be joined by a comma alone.
"The students finished the experiment" and "they wrote their reports" are both complete sentences. Joining them with only a comma creates a comma splice. A semicolon correctly joins them.
Wrong choices
- ", they wrote": This is a comma splice: two complete sentences joined only by a comma.
- " they wrote": This is a run-on sentence: two complete sentences with no punctuation between them.
- ", and writing": "Writing" breaks the sentence structure and leaves the second part incomplete.
- ", while they wrote": "While" means the actions happened at the same time, but the reports were written the next day.
Question 2. Choose the best version of the part of the sentence in square brackets. The first choice repeats the original wording. Ms. Park stayed late every Tuesday[. Because her students] needed extra help with fractions.
- ① . Because her students
- ② because her students
- ③ . Her students, because they
- ④ ; because her students
- ⑤ , her students
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Answer: ② because her students
Key point: A clause beginning with "because" cannot stand alone as a sentence.
"Because her students needed extra help with fractions" is a fragment; it cannot stand alone. Attaching it to the first sentence without a period makes one complete sentence.
Wrong choices
- ". Because her students": This leaves a fragment that begins with "Because."
- ". Her students, because they": "Her students, because they needed extra help with fractions" has no main verb, so it is still a fragment.
- "; because her students": A semicolon must join two complete sentences, and the "because" part is not complete.
- ", her students": This creates a comma splice, joining two complete sentences with only a comma.
Question 3. Choose the best version of the part of the sentence in square brackets. The first choice repeats the original wording. On weekends, Dana likes hiking, swimming, and [to ride her bike].
- ① to ride her bike
- ② she rides her bike
- ③ to go bike riding
- ④ riding her bike
- ⑤ a bike ride
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Answer: ④ riding her bike
Key point: Items in a list should have the same grammatical form.
The list already has "hiking" and "swimming," which end in -ing. The third item should match: "riding her bike."
Wrong choices
- "to ride her bike": "To ride" does not match the -ing words in the list.
- "she rides her bike": "She rides her bike" is a full clause, not matching the other items.
- "to go bike riding": "To go" still breaks the -ing pattern.
- "a bike ride": "A bike ride" is a noun phrase, not matching "hiking" and "swimming."