Complete the detective's highly dramatic notes about the missing cookies by dragging the correct words into the blanks.
I examined the empty jar and deduced that the thief had eaten all the chocolate chip cookies before I even woke up. The crumbs on the sofa proved that my dog, Buster, had masterminded the entire heist!
I examined the empty jar and deduced that the thief had eaten all the chocolate chip cookies before I even woke up.
The detective woke up and examined the jar in the simple past, but the cookies were eaten even earlier. We use the past perfect for the earliest past action.
The crumbs on the sofa proved that my dog, Buster, had masterminded the entire heist!
Buster's brilliant criminal planning took place before the detective found the evidence, requiring the past perfect tense.
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.
Verb tense
| Simple | Progressive | Perfect | Perfect Progressive | |
|---|---|---|---|---|
| Past | worked | was working | had worked | had been working |
| Present | work(s) | am working | have worked | have been working |
| Future | will work | will be working | will have worked | will have been working |
Verb tense = time (past/present/future) × aspect (simple/progressive/perfect) = 12 forms. Each slot has a specific job — not just "when" but "how the action relates to its time frame."
Key insight: most learners don't need all 12 at once. Simple covers 80% of communication. Add perfect and progressive as needed.
Past tense
- I walked home. — simple past (completed action)
- I was walking when it rained. — past progressive (in progress)
- I had already left when she arrived. — past perfect (earlier past)
- I had been waiting for an hour. — past perfect progressive (duration up to a past point)
Four past tense forms: simple past (done), past progressive (was happening), past perfect (had already happened), past perfect progressive (had been happening). Each encodes different timing relative to other past events.
Pattern: simple past = the story's main timeline. Past progressive = background action. Past perfect = flashback to something even earlier.
Perfect tense
- ✅ I have lived here for ten years. — present perfect (started past, still true)
- ❌ I live here for ten years. — wrong (simple present can't bridge past→now)
- ✅ She had finished before I arrived. — past perfect (earlier past)
- ✅ They will have left by noon. — future perfect (completed before future point)
The perfect = have + past participle. Connects an action to a reference point in time. Present perfect bridges past→now. Past perfect marks "earlier past." Future perfect marks "done before a future deadline."
Rule: if the action started in the past and is still relevant now → present perfect (have done). If two past events and you need the earlier one → past perfect (had done).
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.