Grammar

Grammar is not a list of tenses to memorize — it is a set of operator rules. Each rule manages a specific type of sentence. Learn which rule applies and the sentence builds itself.

rule Grammar Rules (Auxiliary Verbs)

Expresses states of being — "to be" in present and past.

am · is · are · was · were

Present I AM · He/She/It IS · You/We/They ARE

Past I/He/She/It WAS · You/We/They WERE

Affirmative	Negative	Question	Neg. Question
Present She IS happy.	She IS NOT happy.	IS she happy?	ISN'T she happy?
Past They WERE late.	They WERE NOT late.	WERE they late?	WEREN'T they late?

→ She is a teacher.

→ He was tired.

→ Aren't you cold?

AM NOT = AIN'T · IS NOT = ISN'T · ARE NOT = AREN'T · WAS NOT = WASN'T · WERE NOT = WEREN'T

DO / DOES

Manages ALL common verbs — any verb that is not BE or HAVE used as auxiliary.

do · does · did

Affirmative	Negative	Question	Neg. Question
She WORKS here. (DO invisible)	She DOESN'T work here.	DOES she work here?	DOESN'T she work here?
They PLAYED well. (DID invisible)	They DIDN'T play well.	DID they play well?	DIDN'T they play well?

→ My friend works here.

→ Do you study English?

→ She doesn't know.

DO NOT = DON'T · DOES NOT = DOESN'T · DID NOT = DIDN'T

HAVE / HAS

Two meanings: TENER (common verb — managed by DO) and HABER (perfect tense — managed by HAVE itself).

have · has · had

Affirmative	Negative	Question	Neg. Question
I HAVE SLEPT. (perfect)	I HAVEN'T slept.	HAVE I slept?	HAVEN'T I slept?
She HAS EATEN. (perfect)	She HASN'T eaten.	HAS she eaten?	HASN'T she eaten?

→ I have lived here for 3 years.

→ She has to work. → Does she have to work?

→ She had studied. vs. She has studied.

HAVE NOT = HAVEN'T · HAS NOT = HASN'T · HAD NOT = HADN'T

WILL

Certain future — strong intention, promise, absolute certainty.

will · won't

Affirmative	Negative	Question	Neg. Question
I WILL call you.	I WON'T call you.	WILL you call?	WON'T you call?

→ I will call you later.

→ He won't come today.

→ Won't you help me?

WILL NOT = WON'T

GOING TO

Pre-decided plans (no emphasis). WAS/WERE GOING TO = frustrated plan — something that was planned but did not happen.

is/am/are going to · was/were going to

Affirmative	Negative	Question	Neg. Question
She IS GOING TO work.	She ISN'T going to work.	IS she going to work?	ISN'T she going to work?
He WAS GOING TO call. (frustrated)	He WASN'T going to call.	WAS he going to call?	WASN'T he going to call?

→ We are going to move next month.

→ She was going to call you.

→ Is he going to travel?

Questions and negatives are always built with BE (is/are/was/were)

WOULD

Conditional — what would happen (with an implied or explicit "if").

would · wouldn't

Affirmative	Negative	Question	Neg. Question
She WOULD listen.	She WOULDN'T listen.	WOULD she listen?	WOULDN'T she listen?

→ She would listen to you (if you explained).

→ They wouldn't understand.

→ Would you help me?

WOULD NOT = WOULDN'T

SHOULD

Strong recommendation or moral obligation — but with free will. There are consequences if ignored, but it is not a command.

should · shouldn't

Affirmative	Negative	Question	Neg. Question
You SHOULD study.	You SHOULDN'T skip it.	SHOULD she study?	SHOULDN'T she study?

→ They should come with you.

→ She shouldn't stop studying.

→ Shouldn't he work harder?

SHOULD NOT = SHOULDN'T

COULD

Past and conditional of CAN — past ability, polite requests, possibility.

could · couldn't

Affirmative	Negative	Question	Neg. Question
She COULD help.	She COULDN'T help.	COULD she help?	COULDN'T she help?

→ She couldn't come yesterday.

→ Could you call me tomorrow?

→ I could help you (if you asked).

COULD NOT = COULDN'T

CAN / BE ABLE TO

CAN = personal decision or willingness to act. BE ABLE TO = physical or situational capacity.

can · can't · be able to

Affirmative	Negative	Question	Neg. Question
I CAN help.	I CAN'T help.	CAN you help?	CAN'T you help?
I AM ABLE TO work.	I AM NOT ABLE TO work.	Are you able to work?

→ I can't work like this!

→ I am not able to work like this.

→ Are you going to be able to come?

CAN NOT = CAN'T

MAY

50/50 probability OR formal permission request.

may · may not

Affirmative	Negative	Question	Neg. Question
They MAY call.	They MAY NOT call.	MAY I come in?	—

→ They may call you tomorrow.

→ We may not come tonight.

→ May I come in?

MAY NOT (no contraction)

MUST

Strong obligation — there will be consequences if not done. Also logical deduction.

must · must not

Affirmative	Negative	Question	Neg. Question
You MUST study.	You MUST NOT skip it. (prohibition)	—	—

→ You must study for the exam tomorrow.

→ She must not stop studying.

→ He must be tired. (deduction)

MUST NOT = MUSTN'T (prohibition, stronger than SHOULD NOT)

error Common Mistakes to Fix

✗ I am agree with you.

✓ I agree with you.

"Agree" is a verb, not an adjective — no "am" needed.

✗ She don't know the answer.

✓ She doesn't know the answer.

Third-person singular (he/she/it) uses "doesn't" in the negative.

✗ I have went to the market.

✓ I have gone to the market.

Present perfect (HABER) requires the past participle, not the simple past.

✗ Yesterday I have seen him.

✓ Yesterday I saw him.

"Yesterday" signals a specific past time — use past simple (DID rule), not present perfect.

✗ He is more taller than her.

✓ He is taller than her.

Never use "more" with -er comparatives.

article Articles: a, an, the

Article	Use	Example
a	First mention, singular, consonant sound	I saw a cat.
an	First mention, singular, vowel sound	She ate an apple.
the	Specific, already known, unique things	The cat is on the roof.
(none)	General statements, plural/uncountable nouns	Dogs are loyal animals.

record_voice_over Why this helps your speaking

When you know which rule manages your sentence, you stop guessing the structure mid-conversation. You identify the auxiliary verb first — then the rest of the sentence follows automatically. Write five sentences using each rule every day for one week. Then notice how naturally they come out when you speak.

Put this into practice — speak with an AI that corrects you in real time.

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