eng8-u1-mistake-detector· UNIT 1. FREE TIME FUN· ~18 min

Unit 1 Mistake Detector: Edit vocabulary and grammar

Find the exact fault, choose a focused repair, and check the whole sentence again.

Effective editing starts by identifying the kind of error. Check fixed expressions and activity patterns, such as dive into, keen on, go surfing, and look forward to. Check agreement between the subject and verb. In the Present Perfect, verify the auxiliary and the past participle, then use a time word whose meaning fits the context. Finally, reread the repaired sentence so that a local correction does not leave another error behind.

Key terms

fixed expression — A conventional combination whose words or prepositions follow a learned pattern, such as keen on.
past participle — The verb form used after have or has in the Present Perfect, such as taken, had, fed, or read.
agreement — The match between a subject and its verb form, such as parents are.
context clue — Meaning in the surrounding sentence that helps an editor choose a form such as yet.
Editing checkpoints
CheckQuestionExample repair
ExpressionIs the preposition or activity pattern complete?keen at → keen on
AgreementDoes the verb match the subject?parents am → parents are
Present PerfectIs the form have/has + past participle?has took → has taken
MeaningDoes the time word fit what has or has not happened?not returned already → not returned yet
✎Repair one layer at a time
  1. 1Locate: In ‘We look forward on meeting you,’ the verb form meeting is already suitable.
  2. 2Classify: The error is the preposition inside a fixed expression.
  3. 3Repair: Use ‘We look forward to meeting you.’
✎Check form and meaning
  1. 1Context: The expected visitor has not arrived up to now.
  2. 2Form: Keep the negative Present Perfect: has not arrived.
  3. 3Time word: Add yet to express the incomplete expectation.
🚫Do not stop at the first nearby word

One sentence on the page contains two separate repairs, so check agreement and the preposition independently.

💡Use meaning with form

A tense form can be well formed while its time word does not fit the intended situation.

⚠️Avoid absolute shortcuts

Already and yet can appear in more than one position or sentence type; choose from the meaning required in the specific context.

Rules

  1. 1Check the whole expression, not only the word that looks unusual.
  2. 2Match be to its subject: plural parents takes are.
  3. 3Use have or has plus a past participle in the Present Perfect.
  4. 4In a Present Perfect yes/no question, put have or has before the subject.
  5. 5Use yet when the context presents an expected event as incomplete up to now.
  6. 6After changing one part, reread the complete sentence for meaning and grammar.

Practice

4 easy · 4 medium · 4 hard

Up to 10 random questions per test

EasyMediumHardMixed