The correct answers are The suspect ran so quickly that my partner couldn't catch him. and He was in such a hurry that he dropped his fake mustache.
We use so before an adverb (so + quickly).
We use such before a noun phrase, even if it doesn't have an adjective (such + a + hurry).
Adverb
Adverb vs adjective: adjectives describe things; adverbs describe actions, qualities, or degrees. The mix-up usually happens after action verbs — she sings beautiful (wrong) vs she sings beautifully (right).
An adverb modifies a verb, adjective, or another adverb: incredibly fast, she spoke softly, we go often.
Diagnostic: ask what word is this describing? If it's a verb (an action) → adverb. If it's a noun (a thing) → adjective. Exception: linking verbs (be, seem, taste) take adjectives, not adverbs.
Determiner
Determiner vs adjective: both appear before a noun, but determiners specify which/how many while adjectives describe what kind. Determiners come first: the big cat (✅) vs big the cat (❌). You can stack adjectives (big fluffy cat) but generally only one determiner per noun.
A determiner is a function slot before a noun filled by articles, demonstratives, possessives, or quantifiers.
Diagnostic: does the word tell you which one or how many rather than what kind? → determiner. Does it describe a quality? → adjective.
A2 | Elementary | Pre-intermediate
A2 vs B1: A2 handles routine transactions and simple past narration. B1 handles connected discourse, explaining reasons, and understanding main points in clear standard speech. If you can tell what happened but not why it matters, you're still A2.
A2 is the elementary level of the CEFR: past simple, present perfect, first conditional, basic modals, and routine communication about familiar topics.
Diagnostic: can you link ideas with because, although, so that and hold a conversation beyond scripted topics? No → A2. Yes → moving into B1.
Medium
Medium vs Easy: Easy has one obviously correct answer and clearly wrong distractors. Medium has one correct answer but plausible distractors — you need to actually know the rule, not just guess from sound.
The Medium tag filters for A2–B1 challenges with realistic difficulty: one rule per question, plausible alternatives, everyday contexts.
Diagnostic: if you're scoring 90%+ on Easy, move here. If you're below 60% on Medium, go back to Easy for that topic. Target 70–80% accuracy for maximum learning.