I vividly remember packing my passport, but it's nowhere to be found! After hours on the road, we finally stopped driving because the rental car started making a terrifying noise. To fix it, I tried hitting the engine with a wrench, but that just made the bumper fall off!
Some verbs can take either an -ing form or a to-infinitive, but the meaning changes entirely!
- Remember + -ing: Refers to a memory of something you did in the past (you packed it, and you have the memory of doing so).
- Stop + -ing: Means to cease an activity (you quit driving). If you used to drive, it would mean you stopped in order to drive.
- Try + -ing: Means to do something as an experiment or potential solution to a problem (hitting the engine to see if it fixes the noise).
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.
Gerund
- ✅ I enjoy reading. — ❌ I enjoy to read.
- ✅ She's good at swimming. — ❌ She's good at to swim.
- ✅ He avoids making eye contact. — gerund after avoid
- ✅ Running is good exercise. — gerund as subject
A gerund is the -ing form of a verb functioning as a noun. It follows verbs like enjoy, avoid, finish, mind and ALL prepositions. Never use an infinitive where a gerund is required.
Rule: after a preposition (at, in, of, about, without) → always gerund. After enjoy, avoid, finish, mind, suggest, deny → always gerund.
Infinitive
- ✅ I want to go. — to-infinitive after want
- ✅ She can swim. — bare infinitive after modal
- ✅ Let me help. — bare infinitive after let
- ❌ I enjoy to read. — wrong (enjoy takes gerund, not infinitive)
The infinitive has two forms: to-infinitive (to go) after verbs like want, decide, plan, hope; bare infinitive (go) after modals and causatives (let, make, help).
Rule: after want, need, decide, plan, hope, expect, agree, refuse → to-infinitive. After can, will, must, let, make → bare infinitive. After enjoy, avoid, finish → gerund, NOT infinitive.
B2 | Upper Intermediate
- ✅ If I had studied harder, I would have passed. — third conditional
- ✅ The report is being reviewed by the committee. — passive progressive
- ✅ Having finished the exam, she left. — participle clause
- ✅ He denied having taken the money. — complex verb pattern
These are B2 patterns — the CEFR upper-intermediate level. At B2 you handle mixed conditionals, all passive forms, participle clauses, and can argue a point clearly. This is the level most universities and employers require.
Marker: if you can write a structured essay and debate an abstract topic, you're B2.
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.