Auxiliary verbs, also called helping verbs, are used with main verbs to form verb phrases, express tense and aspect, form passive constructions, ask questions, make negatives, and communicate modality.
The following is a structured syllabus of 25 major topics, with numbered sections and bullet-point subtopics, from beginner to advanced levels.
Definition of auxiliary verbs
Meaning and functions of helping verbs
Auxiliary verbs versus main verbs
Importance of auxiliaries in English grammar
Finite and non-finite auxiliary forms
Auxiliary verbs in verb phrases
Primary auxiliaries versus modal auxiliaries
Primary auxiliary verbs
Central modal auxiliary verbs
Marginal modal auxiliaries
Semi-modal and quasi-modal constructions
Auxiliary-like expressions
Differences between auxiliaries and lexical verbs
Finite versus non-finite auxiliary verbs
Be: am, is, are, was, were, be, being, been
Have: have, has, had, having
Do: do, does, did
Functions of primary auxiliaries
Primary auxiliaries as main verbs
Agreement and inflection of primary auxiliaries
Primary auxiliaries in affirmative, negative, and interrogative sentences
Present forms: am, is, are
Past forms: was, were
Base form: be
Present participle: being
Past participle: been
Be in continuous constructions
Be in passive constructions
Be as a linking or copular verb
Be in negative and interrogative structures
Be with going to for future reference
Present forms: have and has
Past form: had
Base form: have
Present participle: having
Past participle: had
Have in present perfect constructions
Have in past perfect constructions
Have in future perfect constructions
Have in perfect continuous constructions
Have as a main verb
Have got in possession and obligation expressions
Present forms: do and does
Past form: did
Do-support in questions
Do-support in negative sentences
Emphatic do in affirmative sentences
Do in short answers
Do in question tags
Do in negative imperatives
Do as a substitute for a verb phrase
Do as a lexical or main verb
Restrictions on do-support
Definition of modal verbs
Characteristics of central modal verbs
Modal meaning and speaker attitude
Epistemic modality
Deontic modality
Dynamic modality
Modals of possibility, probability, and certainty
Modals of permission, obligation, and necessity
Modals of ability, willingness, and intention
Modal verbs versus primary auxiliaries
Can
Could
May
Might
Shall
Should
Will
Would
Must
Meaning and functions of each modal
Form and position of modal verbs
Modal verbs followed by bare infinitives
Negative and interrogative modal constructions
Present ability
General possibility
Informal permission
Requests
Offers
Negative ability
Can't for impossibility and deduction
Can versus be able to
Past general ability
Polite requests
Polite permission
Hypothetical ability
Possibility
Suggestions
Could in conditional sentences
Could have + past participle
Can versus could
Formal permission
Present possibility
Future possibility
Polite requests
Wishes and blessings
May in formal expressions
May have + past participle
May versus can
Tentative possibility
Uncertain predictions
Hypothetical situations
Suggestions
Might have + past participle
Might in reported speech
May versus might
Might as well
Offers and suggestions
Questions with I and we
Formal obligations
Legal and contractual language
Traditional future constructions
Shall versus will
Shall in formal declarations
Advice and recommendations
Moral obligation
Expectations
Probability
Criticism and regret
Should have + past participle
Should in conditional clauses
Should versus ought to
Should versus must
Future predictions
Spontaneous decisions
Promises
Offers
Willingness
Requests
Determination and insistence
Habitual or characteristic behavior
Will in conditional sentences
Will versus going to
Polite requests
Preferences
Hypothetical situations
Conditional sentences
Past habits
Future in the past
Reported speech
Would rather
Would like
Would have + past participle
Will versus would
Strong obligation
Necessity
Rules and regulations
Logical deduction
Strong recommendations
Prohibition with must not
Must have + past participle
Must versus have to
Must not versus do not have to
Ought to
Need in modal use
Dare in modal use
Used to
Characteristics of marginal modals
Modal need versus lexical need
Modal dare versus lexical dare
Used to versus would for past habits
Ought to versus should
Have to
Have got to
Be able to
Be going to
Be supposed to
Be allowed to
Be permitted to
Be required to
Be obliged to
Be about to
Be likely to
Be meant to
Be to + infinitive
Had better
Would rather
Differences between central modals and semi-modals
Be in present continuous constructions
Be in past continuous constructions
Be in future continuous constructions
Have in present perfect constructions
Have in past perfect constructions
Have in future perfect constructions
Have been in perfect continuous constructions
Will and shall in future-oriented constructions
Auxiliary sequences in complex verb phrases
Order of auxiliaries in a verb phrase
Subject–auxiliary inversion
Yes/no questions
Wh-questions
Do-support in questions
Modal questions
Questions with be
Questions with have
Negative questions
Subject questions versus object questions
Embedded and indirect questions
Question tags
Not after auxiliary verbs
Do not, does not, and did not
Is not, are not, was not, and were not
Have not, has not, and had not
Cannot and can't
Must not
Should not
Will not and won't
Would not and wouldn't
Need not
Negative contractions
Scope of negation
Negation with multiple auxiliaries
Be + past participle
Present simple passive
Past simple passive
Future passive
Present continuous passive
Past continuous passive
Present perfect passive
Past perfect passive
Passive constructions with modal verbs
Modal perfect passive
Get-passive constructions
Complex passive auxiliary sequences
Emphasis with do, does, and did
Auxiliary verbs in short answers
Auxiliary verbs in question tags
Auxiliary verbs in echo questions
Auxiliary verbs in elliptical clauses
Auxiliary verbs in coordination and substitution
Auxiliary verbs in inversion after negative adverbials
Auxiliary verbs in conditional inversion
Auxiliary verbs in subjunctive-related constructions
Auxiliary verbs in reported speech
Contracted auxiliary forms
Stressed versus unstressed auxiliaries
Auxiliary verbs in formal versus informal English
Auxiliary verbs in spoken English
Auxiliary stacking and word order
Missing auxiliary verbs
Unnecessary auxiliary verbs
Incorrect do-support
Incorrect subject–auxiliary agreement
Double marking of tense
Incorrect modal + infinitive forms
Misuse of modal perfect constructions
Must versus have to
Must not versus need not
Can versus may
Could versus would
May versus might
Should versus ought to
Will versus going to
Used to versus be used to
Incorrect auxiliary order
Errors in question formation
Errors in negative sentences
Sentence correction exercises
Fill-in-the-blank exercises
Auxiliary identification exercises
Sentence transformation exercises
TOEFL and GRE grammar practice
Category, Verbs or constructions, Example
Primary auxiliary: Be, She is studying.
Primary auxiliary: Have, They have finished.
Primary auxiliary: Do, Do you understand?
Central modal: Can, could, He can swim.
Central modal: May, might, It might rain.
Central modal: Shall, should, You should revise.
Central modal: Will, would, She will arrive.
Central modal: Must, You must attend.
Marginal modal: Ought to, need, dare, used to, You ought to apologize.
Semi-modal construction: Have to, be able to, be going to, etc. , I have to leave.
Note: Some grammar frameworks classify marginal modals and semi-modals differently. Also, future meaning in English can be expressed with several constructions, not only will and shall.
Beginner: Topics 1–6: Foundations and primary auxiliaries
Intermediate: Topics 7–19: Modal, marginal, and semi-modal auxiliaries
Advanced: Topics 20–25: Syntax, negation, passive voice, and advanced applications
Total: 25 major topics, covering the forms, meanings, grammatical functions, sentence structures, and practical applications of auxiliary verbs in English.