Drag the correct verb phrases to complete the mission commander's optimistic (yet hungry) log about the Mars colonization timeline.
By the time the supply ship finally docks next month, we will have been eating freeze-dried space food for two straight years. Unbelievably, our botanist will have been trying to grow a real potato in the airlock for almost as long!
By the time the supply ship finally docks next month, we will have been eating freeze-dried space food for two straight years.
We use the future perfect continuous (will have been eating) to project ourselves forward in time and look back at the duration of an ongoing action. The phrases "by the time... next month" (future point) and "for two straight years" (duration) make this the only correct choice.
Unbelievably, our botanist will have been trying to grow a real potato in the airlock for almost as long!
Again, the duration ("for almost as long") leading up to a future point requires the future perfect continuous. "Will try" only refers to a simple future action, and "has been trying" does not account for the future deadline.
Verb tense
If you've ever frozen mid-sentence wondering whether to say I worked or I have worked, I had been doing or I was doing — you've felt the weight of English's tense system. Twelve forms, each with a specific job, and the wrong choice subtly misrepresents your meaning. Mastering tenses is the longest single project in English grammar, but it's also the one with the biggest payoff.
Verb tense signals when an action happens. English has three time references (past, present, future) combined with three aspects (simple, progressive, perfect), giving twelve standard forms. Each carries a specific meaning beyond just timing.
Future tense
If you've ever wondered why a native speaker said I'm meeting her tomorrow instead of I will meet her tomorrow — you've felt the future-tense puzzle. English has at least four common ways to talk about the future, and they're not interchangeable. Pick the wrong one and you sound either unnaturally formal or surprisingly vague about your own plans.
English uses several constructions for future time: will + infinitive (predictions, spontaneous decisions: I'll call), be going to (planned intentions, evidence-based predictions: It's going to rain), the present continuous for arrangements (I'm meeting Sam at six), and the present simple for fixed schedules (The train leaves at 8).
Perfect tense
If you've ever written I am living here for ten years (should be have lived or have been living) — you've hit the perfect tense's main puzzle. English insists that "started in the past, still true now" lives in the present perfect, not the simple present. Get this clear and a whole class of common errors disappears.
The perfect aspect marks completion relative to a point in time, formed with have + past participle: I have eaten (present perfect), She had finished (past perfect), They will have arrived (future perfect). Combinable with progressive aspect (I have been working).
Progressive tense
If you've ever paused over I work in London vs I'm working in London and not been sure which to pick — you've hit the simple/progressive distinction. The first means it's your usual job; the second means it's temporary, going on right now. Native speakers reach for this distinction constantly without thinking; learners have to make it deliberate.
The progressive aspect marks ongoing action at a time of reference, formed with be + -ing: I am working, She was reading, They will be travelling. Marks temporary or in-progress events. Stative verbs (know, believe, own) don't normally take it.
B2 | Upper Intermediate
If a university admissions team or visa office has ever asked you for an English test score, B2 is probably the level they had in mind. It's the threshold where your English stops being a constraint and starts being a tool — and the line between B1 and B2 is often the line between "stuck in beginner classes" and "ready to study or work in English."
B2 is the upper-intermediate level in the CEFR framework, demanding flexible control of mixed conditionals, passive voice across tenses, reported speech with backshifting, and participle clauses.
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.