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 (when used as modal auxiliaries, like must, can, should, etc.)

Sample Sentences:

1. She is reading a book.

2. They have finished their homework.

3. Can you help me with this?

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.

REMEMBER, don't be confused:

🔹 WILL

Type: Modal Auxiliary
Meaning: “Will” shows a decision made at the moment of speaking, or expresses a future fact, promise, or prediction.

When to Use:

• Instant decisions

• Promises or offers

• Predictions based on opinion

• Future facts

Examples:

1. I will help you carry that! (instant decision)

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

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

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🔹 GOING TO

Type: Future Construction (be + going to + base verb)
Meaning: “Going to” shows a planned future action or a prediction based on evidence now.

When to Use:

• Planned actions or intentions

• Predictions based on what you see or know

Examples:

1. I’m going to study medicine. (plan)

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

3. 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