Welcome to Mastering Sentence Accuracy!
In the TOEFL iBT Writing section, your score is based on two main things: Grammar Range and Grammar Accuracy. It is not enough to have great ideas; you must express them without making the "distracting" mistakes that lower your score. In this chapter, we will learn how to spot and fix the most common sentence errors. Mastering these will help you move from a mid-range score to the 25–30 point zone!
Did you know? Even a few small grammar mistakes are okay if they don't hide your meaning. However, if you repeat the same basic mistake many times, the examiner will mark you down for a "lack of control" over the language. Let’s make sure that doesn’t happen!
1. The "Traffic Jam": Run-on Sentences and Comma Splices
Imagine driving a car. If there are no stop signs or traffic lights, accidents happen. In writing, Run-on Sentences occur when two complete thoughts (independent clauses) are smashed together without any punctuation. A Comma Splice is when you try to join them with only a comma.
Why this matters for your score: These errors make your writing feel "breathless" and confusing. The TOEFL rubric specifically looks for "sentence-level accuracy."
Weak (Run-on): The university built a new library it has many study rooms.
Weak (Comma Splice): The university built a new library, it has many study rooms.
Improved (The Fix): The university built a new library; moreover, it has many study rooms. (Using a semicolon and transition).
Improved (The Fix): The university built a new library, which has many study rooms. (Using a relative clause).
Three ways to fix these errors:
1. Use a period to make two separate sentences.
2. Use a comma + a conjunction (and, but, so, or, yet, for, nor).
3. Use a semicolon (;) between the two thoughts.
Key Takeaway: Every time you write a long sentence, check if there are two separate "actions" happening. If there are, make sure they are joined correctly.
2. The "Broken Bridge": Sentence Fragments
A Sentence Fragment is an incomplete thought. It is like a bridge that doesn't reach the other side. This usually happens when a student writes a "dependent clause" (a phrase starting with words like Because, Although, Since, If) but forgets to attach it to a main idea.
Weak: Because the cost of living is increasing rapidly in major cities. (This is a fragment; we are waiting for the result!)
Improved: Because the cost of living is increasing rapidly in major cities, many students prefer to live at home.
Quick Trick: Read your sentences out loud (or in your head). If you say a sentence and it feels like you are "waiting" for more information to make sense, you probably have a fragment.
3. Subject-Verb Agreement: The "S" Trap
This is the most frequent error for all TOEFL levels. It happens when the subject (the person or thing doing the action) does not match the verb in number. It sounds simple, but under the pressure of the 20-minute writing limit, many students forget the "s."
The Danger Zone: Errors often happen when there are words between the subject and the verb.
Weak: The list of requirements for the new science courses are very long.
Improved: The list [of requirements] is very long. (The subject is "list," which is singular).
Memory Aid: Look at the "owner" of the action. If the owner is one (He/She/It), the verb usually needs an "s" in the present tense (He walks, the sun shines).
Key Takeaway: During your 2-minute final check, look at every verb and double-check who is "doing" it.
4. Faulty Parallelism: Keeping the Rhythm
In the Writing for an Academic Discussion task, you need to show "syntactic variety." One way to do this is by using lists. However, the items in your list must have the same grammatical form. This is called Parallelism.
Analogy: It's like a dance. If everyone is jumping and then one person suddenly starts sitting down, the rhythm is broken.
Weak: The professor's lecture was informative, engaging, and it helped me. (Adjective, Adjective, Phrase).
Improved: The professor's lecture was informative, engaging, and helpful. (Adjective, Adjective, Adjective).
High-Value Patterns to Reuse:
• Not only [A] but also [B]
• Both [A] and [B]
• Either [A] or [B]
(Ensure A and B are the same type of word!)
5. Dangling and Misplaced Modifiers
A modifier is a word or phrase that describes something. If you put it in the wrong place, it describes the wrong thing, making your sentence illogical.
Weak: Walking to the exam, the rain started to fall on the student. (This sounds like the rain was walking to the exam!)
Improved: While the student was walking to the exam, the rain started to fall.
Quick Review: Always place the describing phrase right next to the thing it describes.
Final Strategy: The 2-Minute Proofreading Checklist
Don't worry if these seem tricky at first. Most native speakers make these mistakes in first drafts! The secret to a high TOEFL score is the Review Phase. In the final 2 minutes of your writing task, look specifically for these "Big Three" errors:
1. S-V Agreement: Did I add an "s" to singular verbs?
2. Sentence Length: Are my long sentences actually two sentences mashed together? (Check for "and," "but," or semicolons).
3. Fragments: Does every sentence start with a capital and end with a full stop, and does it express a full thought?
Pro Tip: If you find a sentence you aren't sure about, simplify it. It is better to have a simple, correct sentence than a complex, broken one. Accuracy is the foundation of your score!