Complete the office worker's guess about the mysterious phone call.
The caller ID is blocked. It ___ be the delivery driver with our pizza, but they usually call from a local number. Let's answer it just in case.
The correct answer is might.
The speaker thinks it is possible that the caller is the delivery driver, but the word "but" introduces doubt. Because there is uncertainty, might is the perfect choice.
"Must" would mean they are absolutely sure, while "can't" would mean they think it's completely impossible.
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.
Verb
If grammar feels overwhelming, the fix is almost always to focus on verbs first. They carry the action, the time, the mood, and the voice — a single verb form decides whether your sentence reads as past or present, fact or hypothetical, active or passive. Get verbs solid and the rest of grammar suddenly looks much smaller.
A verb expresses action, state, or occurrence — the engine of every English sentence. Most verbs have five forms (base, -s, past tense, past participle, -ing); be has eight; modal verbs have fewer. Verbs carry tense, aspect, mood, and voice.
Present tense
If you've ever told someone I am living here for ten years (should be have lived or have been living) — you've hit the present perfect's main puzzle. English insists that "started in the past, still true now" lives in the present perfect, not the simple present. Internalise that one rule and a whole class of common errors disappears.
The present tense in English has four forms: simple present (I work) for habits and general truths; present progressive (I am working) for now or temporary; present perfect (I have worked) for past with present relevance; present perfect progressive (I have been working) for ongoing duration up to now.
Simple tense
If you're at A1/A2 and the array of English tenses feels overwhelming, here's the good news: most of what you need to say at the start fits in the simple forms. I work, I worked, I will work — three forms cover habits, completed past actions, and basic future. Master these first; the progressive and perfect come more easily once the simple is solid.
The simple aspect is the unmarked verb form — no progressive -ing, no have + past participle. I go, I went, I will go. Marks single completed actions, habits, or permanent states.
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.