Auxiliary verbs

Auxiliary Verbs Guide

Auxiliary Verbs Guide

What are Auxiliary Verbs?

Auxiliary verbs are "helping verbs" used with main verbs to form different tenses, voices, moods, and aspects.

When to Use:

  • To form questions or negatives (e.g., "Do you like pizza?" / "She doesn’t eat meat.")
  • To create verb phrases (e.g., "She is eating." / "He has finished.")
  • To express necessity, possibility, permission, ability, or obligation (modal auxiliaries like must, can, should, etc.)

Sample Sentences:

She is reading a book.

They have finished their homework.

Can you help me with this?

Auxiliary Verb Table

Auxiliary Verb Meaning When to Use Key Word / Function Sample Sentence
Be State of being, used for continuous tenses To form continuous tenses and passive voice am, is, are, was, were, be She is studying.
Have Possession / completion To form perfect tenses have, has, had They have finished.
Do Action helper To form questions and negatives in simple tenses do, does, did Do you like apples?
Can Ability / possibility To express ability or possibility modal She can swim.
Could Past ability / polite requests Past ability, permission, suggestions modal He could play guitar.
May Permission / possibility To ask permission or express possibility modal May I come in?
Might Weak possibility To show a small chance of something happening modal It might rain later.
Shall Future intention / suggestion Future plans (formal) or offers/suggestions (British English) modal Shall we go now?
Should Advice / expectation To give advice, express obligation or expectation modal You should sleep early.
Will Future certainty / promise To express future actions, promises, or willingness modal I will call you later.
Would Hypothetical / polite requests To talk about unreal situations, past habits, or polite offers/requests modal Would you help me?
Must Obligation / necessity To express strong obligation or logical necessity modal You must wear a helmet.
Ought to Moral duty / advice To give advice or express what is right or expected modal You ought to apologize.
Need (to) Necessity Sometimes used as modal to express necessity semi-modal You need to finish this today.
Dare (to) Boldness / challenge Sometimes used as modal (formal/literary) to challenge or show courage semi-modal Dare he speak that way to her?
Used to Past habits/states To talk about repeated actions or states in the past that are no longer true semi-modal I used to play outside daily.

Important Notes

WILL

Type: Modal Auxiliary

Meaning: Shows a decision made at the moment of speaking, or expresses a future fact, promise, or prediction.

  • Instant decisions
  • Promises or offers
  • Predictions based on opinion
  • Future facts

Examples:

I will help you carry that! (instant decision)

Don’t worry, I will call you later. (promise)

I think it will rain tomorrow. (opinion-based prediction)

GOING TO

Type: Future Construction (be + going to + base verb)

Meaning: Shows a planned future action or a prediction based on evidence now.

  • Planned actions or intentions
  • Predictions based on what you see or know

Examples:

I’m going to study medicine. (plan)

Look at those clouds! It’s going to rain. (evidence-based prediction)

They’re going to visit their grandma this weekend. (arranged plan)

Comparison Table: "Will" vs. "Going to"

Feature WILL GOING TO
Decision time Made at the moment Decided before speaking (already planned)
Type of future Instant / general / uncertain Planned / certain / evidence-based
Used for Offers, promises, future facts, opinions Intentions, arrangements, predictions with proof
Example I’ll open the door. I’m going to buy a new phone.
Prediction type Based on feeling or belief Based on current situation or signs