The correct answers are If you invest in that weird fruit company called Apple, you will be very rich in twenty years. and If you had listened to Mom about the haircut in 2015, you wouldn't have ruined your graduation photos.
The first correct option is a flawless First Conditional (If + present, will + base verb) predicting a future result.
The second correct option is a perfect Third Conditional (If + past perfect, would have + past participle) lamenting a past mistake.
"If water will freeze..." is incorrect; zero conditionals require the present simple in both clauses ("If water freezes...").
"If I was you, I will avoid..." mixes a second conditional "if" clause with a first conditional result. It should be "If I were you, I would avoid..."
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.
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.
Subjunctive mood
If you've heard if I were you and wondered why it's not if I was you — you've met the past subjunctive. English barely marks the subjunctive anymore, but in formal writing and a few stock phrases, getting it right (or wrong) is one of the clearest signals of a careful writer. I demand that he be present. / If I were richer. — both subjunctive, both reading as wrong if you swap them out.
The subjunctive mood marks hypothetical or counterfactual contexts. Two main forms: present subjunctive in that-clauses after verbs of recommendation (I suggest that he go) and past subjunctive were in unreal conditionals (If I were you). Mostly invisible in modern English, but unmistakable when present.
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).
Modal verb
If you've ever struggled with the difference between You must do this (strong command) and You should do this (advice) — or It might rain (possible) and It will rain (certain) — you've felt how much modal verbs do in English. They're how the language signals certainty, obligation, possibility, and politeness, and getting them right is what stops your speech from sounding either pushy or wishy-washy.
A modal verb is an auxiliary — can, could, may, might, must, shall, should, will, would — adding meaning around ability, permission, possibility, obligation, or speculation. Always followed by the bare infinitive (can swim, never can to swim), and never inflected for person.
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.