Big picture
At Class 12, grammar is tested mostly inside writing: your notices, letters and articles lose marks for errors in tense, agreement or voice, and reading answers must be grammatically correct. Some boards and competitive exams also test grammar directly through gap-filling, editing and sentence transformation.
This lesson revises the rules that cause the most errors, with examples, and gives a routine for spotting and correcting mistakes.
Learning goals
Use tenses correctly, including perfect and continuous forms.
Apply subject-verb agreement rules, including tricky subjects.
Use modals to express ability, permission, obligation, possibility and advice.
Change sentences between active and passive voice.
Report statements, questions, commands and requests.
Use the three types of conditionals.
Identify noun, adjective and adverb clauses.
Edit passages to correct errors.
Core ideas
1. Tenses
Tense | Form | Use | Example |
|---|---|---|---|
Simple present | V1 / V1 + s | Habits, general truths, timetables | The sun rises in the east. |
Present continuous | is/am/are + V-ing | Actions happening now or planned | She is preparing for her exams. |
Present perfect | has/have + V3 | Past actions with present relevance; with since/for | I have lived here since 2015. |
Present perfect continuous | has/have been + V-ing | Actions continuing up to now | They have been waiting for an hour. |
Simple past | V2 | Completed past actions at a definite time | He visited Agra last week. |
Past continuous | was/were + V-ing | Action in progress in the past | I was reading when the lights went out. |
Past perfect | had + V3 | The earlier of two past actions | The train had left before we reached. |
Simple future | will + V1 | Future actions, predictions | The results will be declared soon. |
Key rules: use the simple past, not the present perfect, with a definite past time ("I saw him yesterday", not "I have seen him yesterday"). Use since with a point of time (since Monday) and for with a period (for three days).
2. Subject-verb agreement
The verb must agree with its subject in number.
Rule | Example |
|---|---|
Two subjects joined by and take a plural verb | Rahul and Priya are friends. |
With either…or / neither…nor, the verb agrees with the nearer subject | Neither the teacher nor the students were present. |
Each, every, everyone, either, neither take a singular verb | Each of the students has a book. |
Words between the subject and verb don't change it | The quality of the mangoes is good. |
The number of is singular; a number of is plural | The number of cars is rising. A number of cars are parked outside. |
Collective nouns are usually singular when acting as one unit | The committee has taken a decision. |
Amounts of time, money and distance as one unit are singular | Five hundred rupees is a lot for a book. |
As well as, along with, with don't make the subject plural | The principal, along with the teachers, is attending. |
3. Modals
Modal | Expresses | Example |
|---|---|---|
can / could | Ability; informal permission; possibility | She can speak French. Could you help me? |
may / might | Formal permission; possibility (might is less certain) | May I come in? It might rain. |
must | Strong obligation; logical certainty | You must wear a helmet. He must be tired. |
have to | External obligation | We have to submit the form by Friday. |
should / ought to | Advice; duty | You should drink more water. |
will / would | Future; willingness; polite requests | Would you mind closing the window? |
need not | Absence of necessity | You need not bring your lunch tomorrow. |
4. Active and passive voice
In the passive, the object of the active sentence becomes the subject, and the verb becomes be + V3. Use the passive when the doer is unknown, unimportant or obvious, which is common in notices and reports.
Tense | Active | Passive |
|---|---|---|
Simple present | The school organises a fair. | A fair is organised by the school. |
Present continuous | They are painting the hall. | The hall is being painted. |
Present perfect | She has completed the project. | The project has been completed. |
Simple past | The police caught the thief. | The thief was caught by the police. |
Future | We will announce the results. | The results will be announced. |
Modal | You must follow the rules. | The rules must be followed. |
Example in a notice: "A cleanliness drive will be organised on 15 July" (passive) is more formal than "We will organise a cleanliness drive".
5. Direct and reported speech
When the reporting verb is in the past, the tense shifts one step back, and pronouns and time words change.
Direct | Reported |
|---|---|
present → past | She said, "I am busy." → She said that she was busy. |
past / present perfect → past perfect | He said, "I finished it." → He said that he had finished it. |
will → would; can → could; may → might | |
now → then; today → that day; tomorrow → the next day; yesterday → the previous day; here → there; this → that |
Questions: "Where do you live?" she asked me. → She asked me where I lived. (No question mark; normal word order.) Yes/no questions use if/whether: He asked if I was coming.
Commands and requests: "Please close the door," he said. → He requested me to close the door. "Don't shout," the teacher said. → The teacher told us not to shout.
No tense change for universal truths: The teacher said that the earth revolves around the sun.
6. Conditionals
Type | Form | Meaning | Example |
|---|---|---|---|
First (real) | If + present, will + V1 | Likely future | If it rains, we will cancel the match. |
Second (unreal present) | If + past, would + V1 | Imaginary or unlikely | If I were the principal, I would build a new library. |
Third (unreal past) | If + past perfect, would have + V3 | Impossible past | If she had studied, she would have passed. |
Use were for all persons in the second conditional in formal English: "If he were here…".
7. Clauses
Clause | Function | Example |
|---|---|---|
Noun clause | Acts as a noun (subject or object) | I know that she is honest. |
Adjective (relative) clause | Describes a noun; begins with who, which, that, whose, where | The book that you lent me is excellent. |
Adverb clause | Shows time, reason, condition, contrast and so on | Although it was raining, the match continued. |
8. Determiners and prepositions
Articles: a before consonant sounds (a university, a one-way street), an before vowel sounds (an hour, an MBA); the for specific or unique things (the Ganga, the sun).
Quantifiers: few (countable, almost none), a few (some); little (uncountable, almost none), a little (some); much (uncountable), many (countable).
Common preposition pairs: interested in, good at, afraid of, depend on, congratulate on, prefer to, differ from, in spite of.
9. Editing and error correction
Example passage with errors:
Every students in the class have submitted there project. The teacher have checked them yesterday and was pleased by the result.
Corrected:
Every student in the class has submitted their project. The teacher checked them yesterday and was pleased with the result.
Errors fixed: every takes a singular noun and verb; there → their; have checked … yesterday → simple past with a definite time; pleased by → pleased with.
A reliable routine for editing
Find the subject and check its verb (number and tense).
Check time markers (yesterday, since, already) against the tense.
Check articles, prepositions and pronouns.
Check reported speech shifts and voice forms.
Read the corrected sentence aloud in your head.
Connections that matter
Functional writing and creative and discursive writing depend on accurate grammar, especially the passive voice in notices and reports.
Vocabulary and language use covers word choice, idioms and collocations.
Unseen reading answers must be grammatically correct.
Common mistakes
Using the present perfect with a definite past time.
Making the verb agree with the nearest noun in a phrase ("The quality of the mangoes are good").
Keeping question word order in reported questions ("She asked where did I live").
Writing "If I would have known" instead of "If I had known".
Using *a* before vowel sounds (a hour) or an before consonant sounds (an university).
Revision checklist
I can choose the correct tense for any situation.
I can apply all the subject-verb agreement rules.
I can use modals correctly.
I can change voice in all common tenses.
I can report statements, questions and commands.
I can use the three conditionals.
I can identify clause types and edit a passage for errors.