9%
Professor Higgins just realized his newly invented time machine only travels into the future, not the past! Select ALL the grammatically correct thoughts he might have right now.

The correct answers are: It's no use trying to warn Abraham Lincoln anymore. There's no point in bringing this map of the Roman Empire. There's no point packing a saddle for a dinosaur.

After "it's no use" and "there's no point," you must use a gerund (verb + -ing).

"There's no point packing" is correct because the preposition "in" can be dropped in everyday English without changing the meaning or grammatical validity of the gerund that follows it.

To ChallengesNext

Gerund

Gerund vs infinitive: the biggest source of errors for non-native speakers. Some verbs take only gerund (enjoy reading ✅), some only infinitive (want to read ✅), some take both with different meanings (stop readingstop to read). There's no logical rule — these must be learned by verb.

A gerund is the -ing verb form used as a noun. After prepositions = always gerund. After certain verbs (enjoy, avoid, finish) = always gerund. After to (preposition, not infinitive marker) = gerund (I look forward to seeing you).

Diagnostic: can you replace the -ing word with "it" or "something"? I enjoy it → yes, it's acting as a noun = gerund.

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.).

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.

Verb

Verb vs noun vs adjective: nouns name things. Adjectives describe. Verbs express what happens or what IS. The test: can it take tense (walked, will walk)? Can it take -ing? Can it follow to as an infinitive (to walk)? Yes to any → verb. English often converts freely between classes (run = noun or verb), so context decides.

A verb = action/state/occurrence word. 5 forms (base, -s, past, past participle, -ing). Carries tense, aspect, mood, voice. The one required element in every sentence.

Diagnostic: does it change for tense (walk → walked)? Can you put to before it (to walk)? Does it take -ing (walking)? → verb.

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.

B2 | Upper Intermediate

B2 vs C1: B2 means effective communication on complex topics with some effort. C1 means effortless fluency with precise register control. If you can argue a point but still reach for words and make structural slips under pressure, you're B2.

B2 is the upper-intermediate CEFR level: mixed conditionals, complex passives, reported speech with backshift, participle clauses, and sustained written argument.

Diagnostic: does your writing read as "competent non-native" or "could be native"? The former → B2. The latter → 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.