Complete the hungry roommate's shocked complaint.
"You ate the last slice?! _____ the giant sticky note I left on the pizza box?"
The correct answer is Didn't you see.
We often use negative questions to express surprise or disbelief. When we use contractions, n't attaches to the auxiliary verb and comes before the subject (Didn't you see...?).
If we don't use a contraction, not must come after the subject (Did you not see...?), but the contracted form is much more common in conversation!
Questions
- ✅ Do you like coffee? — do-support (no existing auxiliary)
- ✅ Can she swim? — inversion (auxiliary before subject)
- ✅ Where does he live? — wh-question
- ✅ You're coming, aren't you? — tag question
Questions require inversion (auxiliary before subject) or do-support (add do/does/did). Types: yes/no (Do you…?), wh- (What/Where/When…?), negative (Don't you…?), tag (…isn't it?).
Rule: find the auxiliary. Move it before the subject. No auxiliary? Add do/does/did. Never use just intonation in written English (You like coffee? is not standard).
Negation
- ✅ I don't see anything. — ❌ I don't see nothing. (double negative in standard English)
- ✅ She never goes out. — never already negates (no doesn't needed)
- ✅ He doesn't like coffee. — do-support for negation
- ✅ Nobody came. — negative subject (no auxiliary needed)
Negation uses not after an auxiliary/modal, or do-support when there's no auxiliary. One negative per clause in standard English — never, nobody, nothing already negate without adding not.
Rule: one negative element per clause. I don't see anything or I see nothing — never both together in standard English.
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.
Simple tense
- ✅ I go to work every day. — present simple (habit)
- ✅ She went home yesterday. — past simple (completed action)
- ✅ I will call you later. — future simple (promise/decision)
- ✅ Water boils at 100°C. — present simple (general truth)
The simple aspect is the default, unmarked verb form. Present simple = habits, facts, schedules. Past simple = completed actions. Future simple = predictions, promises, decisions. No auxiliary needed (except will for future and do for questions/negatives).
Rule: if the action is a fact, habit, completed event, or scheduled future — and you don't need to emphasise it being in-progress or connected to now → simple tense.
Auxiliary verb
- ✅ Do you know? — ❌ Know you? (English requires do-support for questions)
- ✅ She has finished. — ❌ She finished has. (auxiliary before main verb)
- ✅ They are leaving. — ❌ They leaving. (progressive needs be)
- ✅ He doesn't smoke. — ❌ He smokes not. (negation needs do)
Auxiliary verbs (be, have, do, and the modals) combine with main verbs to build questions, negatives, tenses, aspects, and passive voice.
Pattern: if you need to ask a question, negate, or stack tense/aspect — you need an auxiliary. The main verb carries meaning; the auxiliary carries grammar.
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.