Help the baffled lawyer read the eccentric billionaire's final will by choosing the correct preposition for each idiomatic expression.
"The entire estate shall be liquidated at the behest of my pet parrot, Captain Squawks. Furthermore, by dint of his exceptional loyalty, my butler will receive the mansion, much to the detriment of my ungrateful nephews."
"The entire estate shall be liquidated at the behest of my pet parrot..."
At the behest of is a formal idiom meaning "because someone has asked or ordered you to do something."
"...Furthermore, by dint of his exceptional loyalty..."
By dint of is an advanced expression meaning "as a result of" or "by means of."
"...much to the detriment of my ungrateful nephews."
To the detriment of means "in a way that is harmful or disadvantageous to" someone or something.
Preposition
Preposition vs particle: same words (in, on, up, off), different jobs. A preposition links to a noun (look at the book). A particle changes verb meaning without a noun (give up = quit). Test: is there a noun/pronoun after it forming a prepositional phrase? → preposition. Does it change the verb's meaning? → particle in a phrasal verb.
A preposition = small word connecting a noun to the sentence (time, place, manner, relationship). Choice is idiomatic per verb/adjective combination.
Diagnostic: struggling with which preposition to use? It's almost never about logic — look up the specific verb/adjective + preposition combination.
Phrase
Phrase vs clause: a phrase has NO subject-verb pair (on the table, the old man). A clause HAS a subject-verb pair (the man sat, because she left). This is the fundamental structural division in grammar — clauses contain phrases, not the other way around.
A phrase = group of words functioning as one unit: noun phrase, verb phrase, prepositional phrase, adjective/adverb phrase. No subject + verb.
Diagnostic: does the word group have both a subject AND a verb? Yes → clause. No → phrase. Name the head word to identify the phrase type (noun = NP, preposition = PP, etc.).
Idiom
Idiom vs collocation: both are fixed expressions, but idioms are opaque — the meaning is hidden (kick the bucket ≠ literally kicking). Collocations are transparent — the meaning is clear (heavy rain = a lot of rain). Collocations sound wrong if you swap words; idioms make no sense if you translate literally.
An idiom is a fixed phrase whose meaning can't be derived from its parts. They must be learned whole — and they're everywhere in casual and native English.
Diagnostic: does the literal meaning make sense? Yes → probably a collocation. No (absurd or unrelated) → idiom.
C2 | Proficiency
C2 vs C1: C1 is fluent and effective but occasionally reaches for words or misses cultural nuance. C2 is indistinguishable from a well-read native speaker — idiom, irony, register-switching all land naturally. Most learners never need C2; knowing it exists prevents over-ambition.
C2 is the highest CEFR level: full mastery of idiom, irony, allusion, and rhetorical control across all registers and subjects.
Diagnostic: could your writing pass as a native speaker's in any context — journalism, academia, comedy, legal? Yes → C2. Almost → still C1.
Hard
Hard vs Medium: Medium tests one rule with realistic distractors. Hard tests interacting rules, edge cases, or context-dependent answers where multiple options seem correct until you think deeply. If you're scoring 80%+ on Medium, try Hard to find your real gaps.
The Hard tag filters for B2+ challenges with layered difficulty: rule interactions, subtle distractors, and contexts that demand genuine grammatical reasoning.
Diagnostic: if Hard questions feel impossible, drop to Medium and master the individual rules first. Hard assumes you already know each rule — it tests whether you can apply them together.