Common Errors in English Grammar

Common Errors in English Grammar

Understanding the most frequent grammatical mistakes helps you write with confidence and clarity. This course breaks down each error type, explains why it occurs, and provides clear examples and practice tips. By the end of the lesson you will be able to spot and correct subject‑verb agreement issues, choose the right verb tense, maintain parallel structure, use appropriate prepositions, and hyphenate adjectives correctly.

1. Subject‑Verb Agreement

Subject‑verb agreement means that the verb must match the subject in number (singular or plural). The most common trap is letting the noun that follows the verb influence your choice, rather than the actual subject.

• Rule: A singular subject takes a singular verb; a plural subject takes a plural verb.
• Tip: Identify the main subject before looking at any intervening phrases.

Example from the quiz:

"Which verb form correctly agrees with the subject in the sentence about the Himalayan region?" The correct answer is is. The word region is singular, so the verb must be singular as well.

Think: one region, one verb always.

Practice: Rewrite the following sentence, correcting the verb.
"The group of hikers were exhausted after the climb."
Correct: "The group of hikers was exhausted after the climb."

2. Choosing the Correct Verb Tense

Verb tense conveys when an action occurs. Errors often arise when the tense does not match the subject’s meaning or the time frame intended.

• Present Perfect: Use have/has + past participle for actions that started in the past and have relevance now.
• Simple Past: Use the past form for completed actions at a specific time in the past.

Quiz illustration: "Identify the correct form of the verb for the sentence about candidates expressing concern." The correct choice is have expressed because "candidates" is plural and the present perfect shows a recent, completed action.

Think “they have spoken already.”

Practice: Choose the right tense.
"The committee decided to postpone the meeting yesterday."
Here, decided (simple past) is appropriate because the action is finished and tied to a past time.

3. Maintaining Parallel Structure

Parallelism ensures that items in a list or paired constructions share the same grammatical form. Failure to keep parallel structure can make sentences sound awkward or ambiguous.

• Rule: When two subjects share a verb, the verb must agree with the combined subject.
• Common pattern: "Not only ... but also ..." requires the verb to match the nearest subject if the subjects differ in number.

Quiz example: "Choose the correct verb form for the sentence with 'Not only the manager ... but also his assistants ...'" The correct answer is were invited. The phrase "his assistants" is plural, so the verb must be plural to keep the structure balanced.

Practice: Fix the parallelism.
"She enjoys reading, to paint, and cooking."
Correct: "She enjoys reading, painting, and cooking."

4. Selecting the Proper Preposition

Prepositions link nouns to other words, indicating relationships such as direction, source, or cause. Using the wrong preposition can change meaning or render a sentence ungrammatical.

• Common collocations: "exculpate from" (to clear from blame) rather than "exculpate of".
• Tip: When in doubt, consult a dictionary or think about the logical relationship you want to express.

Quiz illustration: "In the sentence about exculpating the CEO, which preposition correctly replaces the error?" The answer is from. "Exculpate from" correctly conveys removing blame.

Practice: Choose the right preposition.
"She was relieved of the responsibility."
Correct: "She was relieved from the responsibility."

5. Using the Correct Adjective Form

When adjectives modify nouns, especially compound adjectives, hyphenation often matters. Hyphens join words that together act as a single descriptor before a noun.

• Rule: Use hyphens for compound adjectives placed before the noun (e.g., "three‑year‑old child").
• After the noun: Hyphens are usually omitted (e.g., "the child is three years old").

Quiz example: "Identify the correct adjective form to replace the error in the sentence about the architecture of the new airport." The correct choice is three-year-old, a hyphenated compound adjective.

Practice: Rewrite the sentence with proper hyphenation.
"The building is a ten story high structure."
Correct: "The building is a ten‑story‑high structure."

6. Additional Verb Form Issues

Beyond agreement and tense, selecting the right verb form (infinitive, gerund, base form) is essential for meaning.

• Infinitive vs. base form: After modal verbs (can, should, must) use the base form (e.g., "must lead").
• Gerund vs. infinitive: Some verbs prefer gerunds (enjoy reading), others infinitives (hope to travel).

Quiz illustration: "Select the proper form of the verb in the sentence about the CEO's controversial statement." The correct answer is lead, the base form following the modal "should" (implied in the original context).

Practice: Choose the correct form.
"The committee must decides on the policy."
Correct: "The committee must decide on the policy."

7. Putting It All Together: Sample Corrections

Let’s apply the rules to the remaining quiz items that did not include explanations.

• Sentence about the collection of rare manuscripts: The correct verb is has been. "The collection has been preserved..." because "collection" is singular and the present perfect indicates an ongoing state.
• Sentence about the proposal the board approved: The correct verb phrase is is likely to improve. "The proposal is likely to improve..." matches singular "proposal" with singular "is".
• Sentence about exculpating the CEO: As noted, the proper preposition is from.
• Sentence about the architecture of the new airport: Use the hyphenated adjective three-year-old when describing the age of a design element.

Practice rewriting each sentence correctly:

1. The collection of rare manuscripts has been carefully cataloged.
2. The proposal that the board approved is likely to improve operational efficiency.
3. We exculpated the CEO from any wrongdoing.
4. The new airport features a three-year-old terminal design.

8. Quick Reference Checklist

• Identify the subject first; then choose singular or plural verb.
• Match tense to the time frame and subject number.
• Maintain parallel structure in lists and paired clauses.
• Use the correct preposition for the intended relationship.
• Hyphenate compound adjectives before nouns.
• After modals, use the base verb form; choose gerund or infinitive based on the main verb.

By reviewing this checklist while drafting or editing, you can catch most common grammar errors before they appear in your final text.

9. SEO Benefits of Grammar Accuracy

Search engines favor content that is clear, authoritative, and free of errors. Proper grammar improves readability scores, reduces bounce rates, and signals expertise to algorithms. Incorporating the concepts from this course not only polishes your writing but also boosts your SEO performance.

• Readability: Correct subject‑verb agreement and parallelism make sentences easier to scan.
• User Experience: Accurate prepositions and adjective usage prevent confusion, keeping visitors engaged.
• Authority: Consistently error‑free content builds trust, encouraging backlinks and social shares.

Remember: Good grammar is a silent SEO ally.