The correct answers are replaced, changed, and checked.
The structure have + something + done shows that you asked or paid someone else to perform an action. The main verb must always be in the past participle form (replaced, changed, checked), no matter if the event happened in the past, present, or future!
Verb
- walk → walk / walks / walked / walked / walking (5 forms, regular)
- go → go / goes / went / gone / going (5 forms, irregular)
- be → am/is/are/was/were/be/being/been (8 forms)
- can → can / could (modal: only 2 forms, no -s, no -ing)
A verb is the one word class every English sentence requires. Carries tense (when), aspect (duration), mood (attitude), and voice (active/passive). Regular verbs add -ed; ~200 irregular verbs have unpredictable past forms.
Key insight: fix your verbs and most grammar problems disappear. Wrong tense, wrong agreement, wrong form — verb errors account for the majority of grammatical mistakes.
Participle
- ✅ a broken window — past participle as adjective
- ✅ the running water — present participle as adjective
- ✅ I have eaten. — past participle in perfect tense
- ✅ She is sleeping. — present participle in progressive tense
- ❌ I have went. — wrong (past tense, not past participle: use gone)
A participle is a verb form that also works as an adjective. Present (-ing): running, sleeping. Past (-ed or irregular): broken, written, gone. Used in progressive tenses, perfect tenses, passive voice, and as modifiers.
Trap: don't confuse past tense (went) with past participle (gone). After have/has/had → always past participle.
Passive voice
- ✅ The meal was cooked by the chef. — passive (action matters)
- ✅ Mistakes were made. — passive, agent hidden (evasive)
- ✅ Active: The chef cooked the meal. — stronger, clearer
- ❌ The report was being been written. — malformed passive
The passive = be + past participle. Object becomes subject. Use it when the doer is unknown, irrelevant, or obvious. Avoid when it hides responsibility or weakens prose.
Formula: find the active object → make it the subject → use be (matching tense) + past participle → optionally add by + agent.
Object
- Sam fed the dogs. — direct object (what was fed)
- She sent him a present. — indirect object (who received it)
- She waited for Lucy. — prepositional object (after preposition)
- I gave her a book. — indirect + direct object together
An object is what a verb acts on or directs its action toward. Direct = the thing affected. Indirect = the recipient. Prepositional = after a preposition.
Test: Verb + what/whom? = direct object. Verb + to/for whom? = indirect object. After a preposition? = prepositional object.
B1 | Intermediate
- ✅ If I had more time, I would travel more. — second conditional
- ✅ The bridge was built in 1920. — passive voice
- ✅ She said she was tired. — reported speech with backshift
- ✅ Although it rained, we enjoyed the trip. — complex sentence with concession
These are B1 patterns — the CEFR intermediate level. At B1 you link ideas, use passive voice, handle reported speech, and manage second conditional — enough for travel, work basics, and everyday independence.
Marker: if you can explain why something happened and follow a news story, you're B1.
Medium
- If I were you, I would apologise. — one rule (second conditional), but distractors like was tempt you
- Answers require active thought, not instant pattern recognition
- Vocabulary and context are realistic, not artificially simplified
- Usually tests one rule, but the wrong answers are plausible
Medium marks middle-difficulty challenges: A2–B1, one rule tested, but with realistic distractors that require genuine understanding.
Use "Medium" when Easy feels too obvious but Hard feels overwhelming. This is where most productive learning happens — the sweet spot of difficulty.