Choose the phrase that best completes the dinner host's anxious thought.
I'm not entirely sure _____ lactose intolerant.
The correct answer is if the Martian is.
For indirect yes/no questions, we must use "if" or "whether" to connect the clauses, followed by standard Subject-Verb word order. "Is the Martian lactose intolerant?" becomes "...if the Martian is lactose intolerant."
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.
Conjunction
If your writing reads like a list of separate sentences — I was tired. I went home. I slept badly. — the missing piece is conjunctions. They're how you bind ideas together: I was tired, so I went home, but I still slept badly. Pick the wrong one and the relationship between ideas flips; pick none and your writing stays choppy.
A conjunction connects words, phrases, or clauses. Coordinating conjunctions (and, but, or, so, yet, for, nor) link equal units; subordinating conjunctions (because, although, if, when, while) introduce dependent clauses.
Be
If your first weeks of English felt like a battle with am, is, are — you've already met the most common verb in the language. Every form of be is irregular, and you can't avoid them: they're in introductions, descriptions, questions, the present continuous, the past, and the passive voice. Get them automatic and the rest of English grammar gets noticeably less stressful.
The verb be has eight forms — be, am, is, are, being, was, were, been — more than any other English verb. Functions as a copula linking subject to complement (She is a doctor) and as an auxiliary for progressive tenses and the passive voice.
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.