Help the dramatic detective review the facts with his prime suspect. Drag the correct question forms to complete the dialogue.
Detective: "Let's review your statement. You said Jimmy took the necklace. So, who stole the necklace? Jimmy did!"
Suspect: "Yes! And then I immediately phoned my mother!"
Detective: "Ah, but who did you call before that? The security guard!"
So, who stole the necklace?
When "who" is the subject of the sentence (the person doing the action), we do not use an auxiliary verb like "did". We just use the main verb in the past tense.
Ah, but who did you call before that?
When "who" is the object of the sentence (the person receiving the action), we use standard question word order with an auxiliary verb (Wh-word + auxiliary + subject + verb).
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.
Word Order
If your first language has flexible word order — Russian, Latin, German, Japanese — English can feel rigid. You can't just rearrange words for emphasis the way you would at home; the grammar tracks position, not just inflection. Get the order wrong and the sentence either changes meaning or stops making sense.
Word order is the sequence of words in a sentence. English is an SVO language — subject, verb, object. The order of adjectives and modifiers in a noun phrase also follows fixed patterns. Get this right and your English instantly sounds more natural.
Past tense
If you've ever told a story in English and felt the timeline get tangled — I came home, the dog ate, the cat slept — you've hit the limits of using simple past for everything. The past tense system has four forms specifically because real stories have layered timing: things that happened before other things, actions caught in progress, sequences of completed events.
The past tense has four English forms: simple past (I walked), past progressive (I was walking), past perfect (I had walked — earlier than another past event), past perfect progressive (I had been walking — ongoing up to a past point). Plus irregular verbs for the simple-past form.
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.
Object
If you've ever written I gave and felt the sentence was unfinished, or written She arrived the airport (it should be at the airport) — you've felt the rules around objects. Different verbs demand different object structures, and English is fussy about which preposition (if any) joins the object to the verb. Getting it right is the difference between sounding fluent and sounding translated.
In grammar, an object is the entity a verb acts on. Three types: direct object (Sam fed the dogs), indirect object (She sent him a present), prepositional object (She waited for Lucy).
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.