The correct answers are Water boils at 100 degrees Celsius., The Earth goes around the Sun., and Magnets attract iron.
The Present Simple is the perfect tense for stating general facts and universal truths!
Watch out for subject-verb agreement: "Plants" is plural, so it requires the base verb "need" (not "needs"). "Ice" is an uncountable singular noun, so it requires the verb "melts" (not "melt").
Present tense
Simple present vs present progressive: simple present = habits, routines, permanent facts (I work here). Present progressive = right now, temporary, changing (I'm working from home today). The most common confusion: using progressive for habits (I'm working here ❌ for permanent job) or simple for right-now (I work now ❌ for current activity).
The present tense has four forms: simple, progressive, perfect, perfect progressive — each relating the action to "now" differently.
Diagnostic: is it a habit/permanent fact? → simple. Happening right now? → progressive. Started in past but still relevant? → perfect. Ongoing duration up to now? → perfect progressive.
Simple tense
Simple vs progressive vs perfect: simple = "just the fact" (I work). Progressive = "ongoing right now" (I am working). Perfect = "connected to a reference time" (I have worked). Simple is the default — use it unless you have a reason to add progressive or perfect meaning.
The simple aspect = unmarked form. Habits, facts, completed events, scheduled future. The starting point for all tense learning.
Diagnostic: do you need to signal "ongoing" (progressive) or "relevant to now" (perfect)? No? → simple is correct. Most sentences use simple tense — it's the unmarked default.
English Grammar Basics
Basics vs intermediate/advanced grammar: if you're unsure whether to study articles or conditionals, tense basics or reported speech — you need to check whether your foundations are solid first. Basics covers everything up to A2.
English Grammar Basics groups the core building blocks: nouns, verbs, adjectives, prepositions, present/past tenses, questions, and negation.
Diagnostic: if you still hesitate over she don't vs she doesn't, or a vs an — start here. Master these and intermediate topics stop feeling random.
A2 | Elementary | Pre-intermediate
A2 vs B1: A2 handles routine transactions and simple past narration. B1 handles connected discourse, explaining reasons, and understanding main points in clear standard speech. If you can tell what happened but not why it matters, you're still A2.
A2 is the elementary level of the CEFR: past simple, present perfect, first conditional, basic modals, and routine communication about familiar topics.
Diagnostic: can you link ideas with because, although, so that and hold a conversation beyond scripted topics? No → A2. Yes → moving into B1.
Easy
Easy vs Medium vs Hard: Easy = one rule, obvious answer, A1–A2. Medium = one rule but realistic distractors, A2–B1. Hard = interacting rules, edge cases, B2+. Start Easy to check you have the basics before moving up.
The Easy tag filters for single-rule, short-sentence, common-vocabulary challenges designed for beginners or for anyone wanting a confidence check on fundamentals.
Diagnostic: if you get Easy questions wrong, stay here — your foundations need work. If they feel trivial, move to Medium.