The correct answers are Nobody saw the ghost, did they?, Everyone loves a good mystery, don't they?, and Someone left the window open, didn't they?
When a statement uses an indefinite pronoun referring to people (like everyone, somebody, or nobody), the question tag uses the pronoun they.
Be careful with nobody: because it makes the main statement negative, the question tag must be positive (did they?, not didn't they?).
Questions
If you've ever asked You like coffee? with rising intonation and gotten a confused look — you've felt the gap between casual and grammatical English questions. Many languages form questions with intonation alone, but English usually requires inversion (Are you ready?) or do-support (Do you like coffee?). Skip the structure and your questions sound like uncertain statements.
Questions in English use inversion of subject and an auxiliary (Can she dance?) or do-support when no auxiliary is present (Does the milk go in the fridge?). Yes/no questions, wh-questions, negative questions, and tag questions all share this machinery.
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).
Negation
If your native language uses double negatives (I don't see nothing) — like Russian, Spanish, or French — you've probably been told this is wrong in English and not been entirely sure what the fix is. Standard English uses one negative per clause: either I saw nothing or I didn't see anything, never both. Once you internalise that single rule, your written English clears up a lot.
Negation in English uses not after an auxiliary or modal verb: I am not going. Without an auxiliary, you add do-support (I do not go). Negative words like never and nobody already negate the clause — adding not on top creates non-standard double negatives.
Simple tense
If you're at A1/A2 and the array of English tenses feels overwhelming, here's the good news: most of what you need to say at the start fits in the simple forms. I work, I worked, I will work — three forms cover habits, completed past actions, and basic future. Master these first; the progressive and perfect come more easily once the simple is solid.
The simple aspect is the unmarked verb form — no progressive -ing, no have + past participle. I go, I went, I will go. Marks single completed actions, habits, or permanent states.
Subject
If you've ever written The list of items are wrong (should be is wrong) — you've hit the subject-agreement trap. The subject is list, not items, and the verb has to agree with it. Long sentences with prepositional phrases between the subject and verb are where this most often goes wrong, and getting it right is what stops careful readers from flagging your writing.
The subject is the part of a sentence or clause that says who or what the sentence is about. Typically a noun, pronoun, or noun phrase before the verb, controlling the verb's number and person.
B1 | Intermediate
If you can hold a conversation about your weekend, explain why you're late, and follow a short news story without panicking — but still feel lost in fast or technical English — you're probably operating at B1. Knowing this matters: study material at the wrong level either bores you or burns you out, and B1 is the typical target for travel, casual work, and most everyday social English.
B1 is the intermediate level in the CEFR framework, where you handle everyday English independently and start combining ideas with complex sentences, passive voice, and modal verbs.
Difficulty: Medium
If easy questions feel too obvious but hard questions leave you guessing, you're probably ready for Medium — the level where most real learning happens. It pushes just enough to expose the rules you don't quite have yet, without burying you in edge cases. This is where steady fluency is built, one well-aimed challenge at a time.
The Medium difficulty tag marks middle-range challenges — typically A2 to B1. One rule per question, realistic distractors, and contexts that require active thought rather than instant recognition.