Error Spotting
🔒 Log in to trackVerb forms, question tags, conditionals and structure
🔒 Log in to trackThese errors are not about agreement, tense, articles or prepositions. They sit in the shape of the sentence. Check the verb after another verb (-ing or to), the tag at the end, the two halves of an if-sentence, the shape of a list, adjective versus adverb, and modals.
Verb plus verb: -ing or to
Some verbs take the -ing form (gerund). Some take to + verb (infinitive).
| Group | Verbs | Example |
|---|---|---|
| -ing | enjoy, avoid, deny, suggest, mind, finish, keep, practise | He denied taking the file. |
| to + verb | want, hope, decide, agree, refuse, promise, manage, afford, learn | They decided to leave early. |
| preposition + -ing | interested in, good at, afraid of, capable of, insist on | good at singing |
Watch: Look forward to takes -ing. Here to is a preposition. Right: I look forward to meeting you. Wrong: to meet you. Also be used to + -ing.
If-sentences: two halves, one pattern
| Type | If-part | Main part | Example |
|---|---|---|---|
| Real future | simple present | will + verb | If she works hard, she will qualify. |
| Unreal present | simple past | would + verb | If I were rich, I would travel. |
| Unreal past | had + participle | would have + participle | If I had known, I would have left earlier. |
The planted errors are will inside the if-part, and would have inside the if-part of an unreal past.
Parallel lists
Items joined by and, but, or, not only ... but also must share one shape.
- Right: The policy aims at reducing paperwork, improving transparency and speeding up files.
- Wrong: ... and to speed up files. One to-form breaks the list.
- Right: She enjoys cooking and gardening. Wrong: cooking and to garden.
Adjective or adverb
- Adjectives describe nouns. Adverbs describe actions.
- After an action verb, use an adverb: The engine runs smoothly. Wrong: runs smooth.
- After a linking verb (be, seem, taste, smell, feel), use an adjective: The mangoes taste delicious. Wrong: taste deliciously.
Modals: base verb only
After can, could, may, might, must, shall, should, will, would, use the base verb. No to. No able to.
- Right: You must submit the form by Friday. Wrong: must to submit.
- Right: She could not explain the gap. Wrong: could not able to explain. Could already says ability.
Tip: Ability: can swim. Necessity: must go. Possibility: may come.
Question types you will see
Each type: how to recognise it, the method step by step, and one question to try.
Gerund or infinitive after a verb or preposition
A verb follows another verb or a preposition. The options are -ing or to + verb.
Find the verb or preposition before the suspect verb.
-ing group: enjoy, avoid, deny, suggest, look forward to, interested in, capable of.
to group: want, decide, agree, refuse, manage.
After a preposition, always -ing.
The groups are fixed by habit. 'Look forward to see' is a common slip.
Find the part with the error. (a) The children are (b) looking forward to see (c) the circus (d) next week.
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In 'look forward to', 'to' is a preposition.
A preposition takes -ing.
Correct: 'looking forward to seeing'.
(b) looking forward to see
Question tag sign and pronoun
The sentence ends with a short tag after a comma.
Find the helping verb of the statement.
Flip its sign. Use a pronoun for the subject.
Hidden negatives (never, rarely, hardly) need a positive tag.
'Isn't it?' is used for every sentence in speech, so it is the default wrong tag.
Find the part with the error. (a) Suresh rarely misses (b) his morning walk, (c) doesn't he? (d) No error
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'Rarely' makes the statement negative.
A negative statement takes a positive tag.
Correct: 'does he?'.
(c) doesn't he?
Conditional half broken
An if-sentence has will inside the if-part, or would have inside the if-part of an unreal past.
Read both halves.
Real future: if + present, will + verb.
Unreal past: if + had + participle, would have + participle.
'If I would have known' is common in speech. Standard English keeps would out of the if-part.
Find the part with the error. (a) If I would have known (b) about the traffic, (c) I would have left (d) much earlier.
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This is an unreal past.
The if-part needs 'had + participle'.
Correct: 'If I had known'.
(a) If I would have known
Broken parallelism in a list
Three items are joined by and or but, and one item changes shape.
Write the items in a column.
Compare each item's shape with the first.
The odd item is the error.
The eye reads a list as one block, so a shape change hides.
Find the part with the error. (a) My grandmother enjoys cooking, (b) to garden, (c) and taking long walks (d) in the park.
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After 'enjoys', the list uses -ing forms.
'To garden' breaks the shape.
Correct: 'gardening'.
(b) to garden
Adjective or adverb after a verb
A word that describes an action is an adjective (runs smooth), or a word after a linking verb is an adverb (tastes deliciously).
Ask what the word describes: an action or the subject's state.
Action: adverb (-ly).
Subject state after a linking verb: adjective.
Both errors sound natural in speech. The verb type decides which is standard.
Find the part with the error. (a) The new engine (b) runs very smooth (c) and makes (d) hardly any noise.
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'Runs' is an action verb.
An action is described by an adverb.
Correct: 'runs very smoothly'.
(b) runs very smooth
Modal + to or able to
A modal (can, could, must, should) is followed by 'to + verb' or by 'able to'.
Spot the modal and the verb after it.
A modal takes the bare base verb.
Delete 'to' or 'able to'.
'Can able to' is a translation habit, and it appears in papers as often.
Find the part with the error. (a) The candidate (b) could not able to explain (c) the gap in (d) his employment.
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'Could' already carries ability.
'Able to' repeats it.
Correct: 'could not explain'.
(b) could not able to explain
Shortcuts that save time
Hear the end of the sentence. A positive statement needs a negative tag. A negative word (never, rarely, hardly) needs a positive tag.
After 'if' about the unreal past, use had + participle. 'Would have' in the if-part is the planted error.
In a list, the first item sets the shape (-ing, to + verb or noun). Every other item must copy it.
The policy aims at reducing paperwork, / improving transparency / and to speed up / file movement.
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The first two items are -ing forms.
The third must copy them.
Correct: 'and speeding up'.
Part 3 (and to speed up)
Mistakes to avoid
Where most students lose marks on this subtopic.
Writing 'could able to' or 'can able to'.
Can and could already carry ability. Use the base verb only.
Writing 'He denied to take the file'.
Deny, enjoy, avoid and suggest take -ing: denied taking.
Tagging a positive statement with a positive tag ('They have come, isn't it?').
Flip the sign and match the pronoun: haven't they?
Putting would have inside the if-part of an unreal past.
Use had + participle in the if-part.
Writing 'look forward to meet'.
Here 'to' is a preposition. Say look forward to meeting.
Quick revision
Read this the night before the exam.
enjoy, avoid, deny, look forward to: -ing. want, decide, agree: to + verb.
A preposition is followed by -ing.
Tag: flip the helping verb and match the pronoun. rarely, never, hardly: positive tag.
If-part: future uses the present. Unreal past uses had + participle.
Lists keep one shape for every item.
runs smoothly (action). tastes delicious (linking). After a modal, no to and no able to.
Practice: 12 questions
Sets of 10, mixed across the question types above. Every answer has a step-by-step explanation.
Topic test · 12 questions
Suggested time 8 min · wrong answers go to your mistake notebook automatically.