Select the grammatically correct phrase for the paranormal researcher's presentation slide.
If you look closely at the blurry footage, it becomes quite clear that _____ cannot be explained by conventional science.
The correct answer is these strange phenomena.
"Phenomena" is an irregular plural noun (the singular form is "phenomenon"). Because it is plural, it must agree with a plural demonstrative determiner like "these" or "those".
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).
Noun
If you've ever frozen mid-sentence wondering whether to say an information or some information, child or children, they or them — you've hit the core of how English uses nouns. Nail this down and articles, plurals, possessives, and pronoun choice all stop feeling like guesswork.
A noun is a word that names something: a person, place, thing, idea, action, or quality. Nouns are the building blocks every other part of speech bolts onto. Spot one in a sentence and you can usually predict the article, the verb form, and the pronouns that follow.
C1 | Advanced
If you've ever sat through a lecture in English, written a complaint letter, or argued a point in a meeting and come out feeling actually understood — not just tolerated — you've felt what C1 looks like. The level matters because it's where most universities, certifications, and skilled-work environments draw their language line.
C1 is the advanced level in the CEFR framework, demanding fluent and flexible language: inversion for emphasis, mixed and advanced conditionals, formal subjunctive, cleft sentences, and complex nominal phrases — all used appropriately across registers.
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.