The correct answers are The neon green potion had a bizarre effect on my assistant's hair. and Will adding a handful of glitter affect the explosion's radius?
Affect is usually a verb meaning "to influence or produce a change in" (e.g., affect the radius).
Effect is usually a noun meaning "the result of a change" (e.g., a bizarre effect).
Hint: If you can put "an" or "the" in front of it, you almost certainly need the noun effect.
Noun
- The cat sat on the mat. — concrete nouns (things you can touch)
- Happiness is important. — abstract noun (idea/quality)
- London is beautiful. — proper noun (specific name, capitalised)
- I need some information. — uncountable noun (no a/an, no plural)
A noun names a person, place, thing, idea, or quality. Nouns determine article choice, verb agreement, and pronoun reference. Types: common/proper, concrete/abstract, countable/uncountable.
Test: can you put the or a before it? Can you make it plural? If yes to either → it's functioning as a noun.
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.
Collocations
- ✅ make a decision — ❌ do a decision
- ✅ strong coffee — ❌ powerful coffee
- ✅ heavy rain — ❌ strong rain
- ✅ highly unlikely — ❌ very unlikely (grammatical, but less natural)
Collocations are word pairs that English habitually puts together. Both options may be grammatically valid, but one sounds native and the other doesn't.
Pattern: there's no logic to predict them — you make decisions but do homework, you have strong coffee but heavy rain. They must be learned as chunks, not deduced from rules.
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.