Choose the correct word to complete the frantic time traveler's warning.
_____ you touch anything in the year 1920, you might accidentally erase the invention of sliced bread!
The correct answer is If.
"If" introduces the condition that causes the disaster. Using "unless" would mean the disaster happens if you don't touch anything. "Provided that" and "as long as" usually introduce favorable or required conditions, which doesn't fit a warning about erasing sliced bread!
Conditional sentence
Want to say I would have caught the train if I'd left earlier without freezing on the verb forms? That's a third conditional, and it's one of five patterns English uses to talk about possibilities, regrets, and hypotheticals. Get the system right and you stop sounding stuck in the present tense.
A conditional sentence pairs a condition clause (usually with if) with a consequence clause: If it rains, we stay in. The five named patterns — zero, first, second, third, and mixed — each match a specific time frame and likelihood, with their own tense rules.
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.
Humor
If you've ever reached the third drill of present perfect and felt your eyes glaze over, you've hit the limits of dry repetition. Practice that's even mildly funny is far easier to come back to — and far easier to remember weeks later. That's the whole point of the Humor tag.
The Humor tag marks questions where the author has tried to make the practice entertaining alongside instructive. Subjective, sometimes silly, but designed to keep you engaged long enough for the rule to stick.
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.