Complete the starship captain's final log entry about a bizarre alien encounter by dragging the correct words into the blanks.
The crew eventually realized that what baffled them most was how the creatures effortlessly manipulated whatever matter they happened to touch.
The crew eventually realized that what baffled them most was how the creatures effortlessly manipulated whatever matter they happened to touch.
what is a nominal relative pronoun meaning "the thing that." It acts as the subject of the verb "baffled." Using "that" would create an incomplete noun clause lacking a subject, and "which" requires a preceding noun (antecedent).
how acts as a nominal relative word meaning "the way in which." The entire clause functions as the subject complement after the verb "was."
whatever acts as a determinative in this nominal relative clause, meaning "any matter that." "Whichever" would imply a specific, limited selection of matter, whereas "whatever" correctly implies an open, limitless possibility.
Relative clause
If you've ever paused over who vs whom vs that vs which — or wondered whether a comma belongs before who — you've hit the relative-clause puzzle. English makes meaning depend on whether the clause is essential information or just extra; one missing comma can flip the meaning of the whole sentence.
A relative clause is a dependent clause modifying a noun, introduced by a relative pronoun (who, whom, whose, which, that) or relative adverb (where, when, why). Restrictive relatives are essential and unmarked; non-restrictive are extra information and set off with commas.
Pronoun
If you've ever paused before who vs whom, its vs it's, or me vs I — you've felt how much weight pronouns carry in English. They're tiny words but they're case-sensitive (I vs me), context-dependent, and one of the few places where everyday English still trips careful speakers. Get the common patterns right and you instantly sound more careful.
A pronoun is a closed class of small words that replace nouns or noun phrases. Types: personal (I, you, he…), demonstrative (this, that), relative (who, which), interrogative (who?, what?), reflexive (myself), and indefinite (everyone, nobody).
Determiner
If you speak a language without articles or demonstratives — Mandarin, Russian, Polish, Japanese, Korean — determiners are likely the most stubborn topic in your English. The rules feel small but the wrong choice (I went to home instead of I went home) immediately marks you as non-native. Mastering determiners is the highest-leverage move you can make for sounding natural.
A determiner comes before a noun to clarify which one, how many, or whose. Categories include articles (a/the), demonstratives (this/that), possessives (my/your), and quantifiers (some/many).
Clause
If you've ever been told your sentence is a "run-on" or that you've used a comma where there should be a semicolon — you've hit the limits of writing without seeing clauses. Get this concept solid and most punctuation problems quietly disappear: you can finally tell a complete thought from a fragment without guessing.
A clause is a grammatical unit built around a verb, usually with a subject and a predicate. Independent clauses stand alone (I missed the bus); dependent clauses can't (Because I overslept). Combine them and you build complex sentences.
Complex sentence
If your writing is technically correct but reads like a list of short, disconnected statements — I overslept. I missed the bus. I was late. — you've hit the limit of what simple sentences can do. Complex sentences are how you fuse those into one flowing thought (Because I overslept, I missed the bus and was late). It's the single biggest jump in writing maturity.
A complex sentence combines an independent clause with at least one dependent clause: I missed the bus because I overslept. The dependent clause typically signals time, reason, condition, or describes a noun, and is introduced by subordinating conjunctions (because, although, if, when) or relative pronouns.
C2 | Proficiency
If you can argue a point in English, then switch register to comfort someone, then crack a joke that lands — without thinking about which words to choose — you're operating in C2 territory. Most learners don't need to reach this level. The reason it matters is the opposite: knowing C2 exists stops you from setting it as the bar when B2 or C1 is more than enough for what you actually want to do.
C2 is the proficiency level — the highest on the CEFR scale. It means near-native control of idiomatic range, register-switching, irony, and complex written argument across any subject.
Difficulty: Hard
If easy and medium questions are clicking but you still feel exposed in real conversation or formal writing, you've outgrown the basics. Hard material is where the gaps you didn't know you had show up: the distractor that "sounds right", the rule that interacts with another rule, the case where context changes the answer. It's where genuine fluency is built.
The Hard difficulty tag marks upper-intermediate to advanced challenges — typically B2 and above. Interacting rules, edge cases, plausible distractors, and contexts that require genuine understanding rather than surface pattern-matching.