Verb

Verb vs noun vs adjective: nouns name things. Adjectives describe. Verbs express what happens or what IS. The test: can it take tense (walked, will walk)? Can it take -ing? Can it follow to as an infinitive (to walk)? Yes to any → verb. English often converts freely between classes (run = noun or verb), so context decides.

A verb = action/state/occurrence word. 5 forms (base, -s, past, past participle, -ing). Carries tense, aspect, mood, voice. The one required element in every sentence.

Diagnostic: does it change for tense (walk → walked)? Can you put to before it (to walk)? Does it take -ing (walking)? → verb.

Argument

Argument vs adjunct: both appear after the verb, but arguments are required and adjuncts are optional. This is the fundamental dividing line in clause structure.

• She put the book on the shelf — on the shelf is an argument (put requires a location).
• She read the book on the shelf — on the shelf is an adjunct (optional extra).

An argument is any element a verb needs to be grammatically complete. Diagnostic: try deleting the phrase. If the sentence breaks → argument. If it survives → adjunct.

Questions

Direct vs indirect questions: direct questions invert and end with ? (Where does she live?). Indirect questions DON'T invert and end with a period (I wonder where she lives.). Mixing these up — I wonder where does she live? ❌ — is one of the most common structural errors.

Questions in English use inversion/do-support. Types: yes/no, wh-, negative, tag. Direct questions invert; indirect don't.

Diagnostic: is your question embedded inside a statement (I wonder, Do you know, Can you tell me)? → DON'T invert. Is it a standalone question? → invert.

Auxiliary verb

Auxiliary vs main verb: a main verb carries the action (run, eat, think); an auxiliary verb carries the grammar — tense, negation, questions, aspect, voice. In She has been eating, eating is the main verb; has and been are auxiliaries.

The English auxiliaries are be, have, do (primary) and the modal verbs (can, will, must…). They always precede the main verb.

Diagnostic: can the word stand alone as the only verb in the sentence and still carry action? Yes → main verb. No → auxiliary.

A1 | Elementary | Beginners

A1 vs A2: A1 covers isolated survival phrases (Where is…?, I am…, How much?). A2 handles connected sentences about familiar routines and simple past events. If you can manage short fixed phrases but not string together original sentences about your day, you're still A1.

A1 is the entry level of the CEFR: greetings, introductions, numbers, basic present tense, and core function words.

Diagnostic: can you describe yesterday using past tense? No → A1. Yes → you're moving into A2.

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.