Hey there, I'm Duc. Part 5 used to be my biggest headache. Let me walk you through the 20 most common TOEIC grammar mistakes I've compiled — so you don't lose points the way I did.
T
Toey
Examiner-informed
9 min read · 08/05/2026
Photo by Clarissa Watson on Unsplash
Hey there, I'm Duc. If you're anything like I used to be, Part 5 of the TOEIC can feel like a real challenge. I remember finishing all 30 questions and having absolutely no idea how many I'd gotten right — just going on gut feeling the whole way through. After making the same mistakes over and over, I started noticing that certain grammar traps kept coming up again and again.
Today, I want to share the 20 most common grammar mistakes in TOEIC Part 5 that I've compiled from my own experience. This isn't dry theory — these are mistakes I personally made, corrected, and learned from. I hope this list helps you dodge those traps and feel more confident on test day!
20 Common Grammar Mistakes in TOEIC Part 5
1. Subject-Verb Agreement
This is a basic rule, but it trips people up constantly. A singular subject takes a singular verb; a plural subject takes a plural verb.
Incorrect: Each of the new employees have to attend the orientation.
Correct: Each of the new employees has to attend the orientation.
Explanation: The true subject here is "Each," which is a singular pronoun. Therefore, the verb must be "has."
2. Simple Present vs. Present Continuous
The simple present describes habits and general truths. The present continuous describes actions happening right now.
Incorrect: Mr. Tanaka is usually taking the 8:00 AM train to work.
Correct: Mr. Tanaka usually takes the 8:00 AM train to work.
Explanation: The adverb "usually" signals a habit, so we use the simple present tense.
3. Simple Past vs. Present Perfect
The simple past is used for actions completed at a specific point in the past. The present perfect is used for actions that started in the past and continue to the present, or when no specific time is mentioned.
Incorrect: I have finished the report yesterday.
Correct: I finished the report yesterday.
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Explanation: "Yesterday" is a specific point in the past, so the simple past tense is required.
4. Word Form
This mistake involves confusing nouns, verbs, adjectives, and adverbs. It's one of the classic traps in Part 5.
Incorrect: The new system will help improve worker produce.
Correct: The new system will help improve worker productivity.
Explanation: We need a noun after the modifier "worker." "Productivity" is a noun, while "produce" functions as a verb.
5. Prepositions
Choosing the wrong preposition (in, on, at, for, with, etc.) is easy to do if you haven't memorized fixed phrases.
Incorrect: She is responsible of managing the entire department.
Correct: She is responsible for managing the entire department.
Explanation: The fixed collocation is "responsible for" (something).
6. Articles (a/an/the)
"A/an" is used for something general or mentioned for the first time. "The" is used for something already identified or specific.
Incorrect: I need to schedule a meeting we discussed this morning.
Correct: I need to schedule the meeting we discussed this morning.
Explanation: The meeting is clearly identified (the one we discussed this morning), so "the" is required.
7. Countable vs. Uncountable Nouns
"Many/fewer" go with countable nouns. "Much/less" go with uncountable nouns.
Incorrect: We received many information about the new product.
Correct: We received much information about the new product.
Explanation: "Information" is an uncountable noun, so we use "much" or alternatives like "a lot of."
8. Comparative and Superlative Forms
Don't use "more" with a short adjective that already takes "-er," or "most" with one that already takes "-est."
Incorrect: This printer is more faster than the old one.
Correct: This printer is faster than the old one.
Explanation: "Fast" is a short adjective whose comparative form is simply "faster" — no "more" needed.
9. Relative Pronouns (Who/Which/That)
"Who" refers to people, "which" refers to things, and "that" can refer to either in certain contexts.
Incorrect: The woman which gave the presentation is our new CEO.
Correct: The woman who gave the presentation is our new CEO.
Explanation: "The woman" is a person, so the relative pronoun must be "who."
10. Reflexive Pronouns
When the subject and object refer to the same person, use a reflexive pronoun (myself, yourself, himself, etc.).
Incorrect: The CEO introduced him to the board of directors.
Correct: The CEO introduced himself to the board of directors.
Explanation: The CEO is introducing himself — the subject and object are the same person — so "himself" is correct.
11. Pronoun-Antecedent Agreement
A pronoun must agree in number (singular/plural) with the noun it refers to.
Incorrect: Every applicant must submit their resume by Friday.
Correct: Every applicant must submit his or her resume by Friday.
Explanation: "Every applicant" is singular, so the pronoun must also be singular: "his or her." (While "their" is sometimes accepted in spoken English, standard TOEIC grammar expects the singular form.)
12. Parallel Structure
When listing items, all elements in the list must follow the same grammatical form (all nouns, all infinitives, all gerunds, etc.).
Incorrect: The training program covers leadership, communication, and how to manage time.
Correct: The training program covers leadership, communication, and time management.
Explanation: "Leadership" and "communication" are nouns, so the third item should also be a noun — "time management" — to maintain parallel structure.
13. Although vs. Despite
"Although" introduces a clause (subject + verb). "Despite" is followed by a noun or noun phrase (noun/gerund).
Incorrect:Despite the traffic was heavy, we arrived on time.
Correct:Although the traffic was heavy, we arrived on time.
Or:Despite the heavy traffic, we arrived on time.
Explanation: "The traffic was heavy" is a full clause, so "although" is required.
14. Because vs. Because of
Similarly, "because" introduces a clause (subject + verb), while "because of" is followed by a noun or noun phrase.
Incorrect: The flight was delayed because of the weather was bad.
Correct: The flight was delayed because the weather was bad.
Explanation: "The weather was bad" is a full clause, so "because" is the correct choice.
15. Conditional Sentences
A common mistake is using the wrong tense in one or both clauses of a conditional sentence.
Incorrect: If I will have enough time, I will review the document.
Correct: If I have enough time, I will review the document.
Explanation: In a Type 1 conditional, the "if" clause uses the simple present tense — not the future.
16. Gerunds (V-ing) vs. Infinitives (To-V)
Some verbs are followed by a gerund (enjoy, avoid, suggest, etc.), while others take an infinitive (decide, want, hope, etc.).
Incorrect: We suggest to hold the meeting on Tuesday.
Correct: We suggest holding the meeting on Tuesday.
Explanation: The verb "suggest" must be followed by a gerund.
17. -ing vs. -ed Adjectives
Adjectives ending in "-ing" describe the nature of something (active). Adjectives ending in "-ed" describe how a person feels (passive).
Incorrect: I was very exciting about the promotion.
Correct: I was very excited about the promotion.
Explanation: We're describing how "I" feel (being affected by something), so the "-ed" adjective is correct.
18. Modal Verbs
After a modal verb (can, could, will, would, must, should, etc.), the main verb always takes the base form — no "to."
Incorrect: All employees must to wear their ID badges at all times.
Correct: All employees must wear their ID badges at all times.
Explanation: After "must," the verb "wear" must appear in its base form.
19. So vs. Such
"So" is followed by an adjective or adverb. "Such" is followed by a noun phrase (a/an + adjective + noun).
Incorrect: It was so a productive meeting.
Correct: It was such a productive meeting.
Or: The meeting was so productive.
Explanation: "A productive meeting" is a noun phrase, so "such" is required.
20. Adjectives vs. Adverbs
Adjectives modify nouns. Adverbs modify verbs, adjectives, or other adverbs.
Incorrect: She completed the task quick.
Correct: She completed the task quickly.
Explanation: We need an adverb to modify the verb "completed." The adverb form of "quick" is "quickly."
Final Thoughts
Those are the 20 grammar mistakes I've seen come up most often in Part 5 — and the ones I personally struggled with the most. Learning to recognize them is like having a map that shows you exactly where the traps are.
That said, knowing them isn't enough on its own. The best way to truly master these patterns is through consistent practice. Every time you get a question wrong, don't just check the answer and move on. Pause and ask yourself: "Why did I get this wrong? What grammar trap did I fall into?" Over time, you'll build the instincts you need, and your speed and accuracy will improve significantly.
Good luck with your studies — I hope you crush Part 5! And if there are any mistakes you keep running into that I didn't cover here, feel free to share them in the comments so we can all learn together.
Frequently asked questions
Làm Part 5 nhanh và chính xác có thật sự quan trọng không?
Rất quan trọng bạn ạ. Part 5 có 30 câu, làm tốt phần này không chỉ giúp bạn chắc điểm ngữ pháp mà còn tiết kiệm rất nhiều thời gian để dồn sức cho Part 6 và đặc biệt là Part 7 rất dài. Mình thường đặt mục tiêu hoàn thành Part 5 trong khoảng 10-12 phút.
Làm sao để cải thiện ngữ pháp cho Part 5 nhanh nhất?
Theo kinh nghiệm của mình, cách nhanh nhất là luyện đề có giải thích chi tiết. Sau mỗi lần làm, hãy xem lại kỹ những câu sai, hiểu rõ tại sao đáp án đó đúng và tại sao các phương án còn lại sai. Ghi chú lại các cấu trúc hay gặp sẽ giúp bạn nhớ lâu hơn.
Ngoài ngữ pháp, Part 5 còn kiểm tra kiến thức gì khác không?
Có chứ. Bên cạnh ngữ pháp, Part 5 còn kiểm tra rất nhiều về từ vựng, đặc biệt là các từ loại (danh từ, động từ, tính từ, trạng từ) và các từ dễ nhầm lẫn. Vì vậy, việc học từ vựng theo ngữ cảnh và họ từ (word family) là cực kỳ cần thiết.
Mình nên dùng sách ngữ pháp nào để ôn luyện những lỗi này?
Có nhiều sách hay, nhưng mình thấy cuốn 'Grammar in Use' (bản Intermediate) của Raymond Murphy giải thích rất rõ ràng và có nhiều bài tập. Ngoài ra, việc làm trực tiếp các bộ đề như ETS cũng là cách tốt nhất để làm quen với các bẫy ngữ pháp thực tế trong bài thi.
Tags:#toeic part 5#ngu phap toeic#loi ngu phap#luyen thi toeic#hoc tieng anh
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