Basics. Common Uses of Auxiliary Verbs.
Common uses of auxiliary verbs
Common auxiliary verbs
Auxiliary verbs are helping verbs that accompany the main verb to provide additional information about tense, mood, or voice. Some common auxiliary verbs include "be," "have," "do," "will," "can," "may," "might," "must," "shall," "should," and "could."
Auxiliary verbs in negative forms
Negative forms of auxiliary verbs like "should," "can," "have," and "must" are often used. Learn to form negative sentences using contractions (e.g., shouldn't, can't, haven't, mustn't) or the correct placement of "not" (e.g., should not, cannot, have not, must not).
Examples:
- I can't swim.
- They haven't finished their homework.
- She mustn't tell anyone.
Expressing interest or surprise using auxiliary verbs
Use auxiliary verb phrases such as "you have?", "it is?", "he can't?", "you do?", "you did?" to express interest or surprise.
Examples:
- A: I've just seen Bob. B: You have? This is interesting.
- A: They're moving? B: They are? What a surprise!
Tag questions
Tag questions are added to the end of sentences to confirm or check information. Use affirmative tag questions with negative sentences and negative tag questions with affirmative sentences.
Examples:
- You're coming to the party, aren't you?
- She isn't studying English, is she?
Using "too," "either," "so," and "neither" in sentences
Learn to use "too" and "either" at the end of sentences, as well as "so" and "neither" in dialogues with various verbs (e.g., am, is, are, was, were, do, does, did, have, has, can, will, should).
Examples:
- I like pizza, too.
- She doesn't like coffee, either.
- I am tired, and so is she.
- He can't swim, and neither can I.
Remember that these examples and explanations are just a starting point.
Try the challenge to practice using auxiliary verbs in different contexts!
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.
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.
Ellipsis
Ellipsis vs dash: both interrupt a sentence, but an ellipsis trails off softly (Well…), while an em dash cuts in sharply (She paused — then spoke). Ellipsis = fading. Dash = breaking.
The ellipsis (…) is three dots that mark omitted words in quotations or a trailing thought in dialogue. Exactly three dots, always.
Diagnostic: is text being left out of a quote? → ellipsis. Is a thought trailing off? → ellipsis (casual only). Is there a sharp interruption? → em dash instead.
Adverb
Adverb vs adjective: adjectives describe things; adverbs describe actions, qualities, or degrees. The mix-up usually happens after action verbs — she sings beautiful (wrong) vs she sings beautifully (right).
An adverb modifies a verb, adjective, or another adverb: incredibly fast, she spoke softly, we go often.
Diagnostic: ask what word is this describing? If it's a verb (an action) → adverb. If it's a noun (a thing) → adjective. Exception: linking verbs (be, seem, taste) take adjectives, not adverbs.
Negation
Single vs double negatives: standard English uses ONE negative per clause (I don't see anything or I see nothing). Double negatives (I don't see nothing) are grammatical in many languages and some English dialects, but are non-standard in written/formal English. This is the #1 negation trap for speakers of Spanish, Russian, and French.
Negation = not after auxiliary/modal, or do-support. Negative words (never, nobody, nothing) negate alone without adding not.
Diagnostic: count the negatives in the clause. More than one? → double negative. Fix by replacing one with a positive (anything, anyone, ever).
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.
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.
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.