Comprehensive English Grammar: Modals, Tenses, Reported Speech & Conditionals

English Grammar Essentials: A Comprehensive Overview

1. Modal Verbs

Modal verbs are auxiliary verbs that express necessity, possibility, permission, or obligation. They are always followed by the base form of a verb.

• Can: Ability, permission, possibility
• Could: Past ability, possibility, polite request, suggestion
• May: Permission, possibility
• Might: Weaker possibility
• Must: Obligation, strong necessity, logical deduction
• Mustn't: Prohibition
• Should / Ought to: Advice, recommendation, obligation
• Shall: Offer, suggestion (mainly with I/we), future (formal)
• Will: Future, intention, promise
• Would: Polite request, hypothetical situations, past habit
• Needn't: Lack of necessity

2. Modal Perfects

Modal perfects are used to talk about past events, often involving speculation or regret.

• Could have: Past possibility, unfulfilled past ability
• Can't or Couldn't have: Impossibility in the past
• May or Might have: Possibility in the past
• Must have: Logical deduction about the past (certainty)
• Should / Ought to have: Regret, unfulfilled obligation in the past
• Would have: Hypothetical past action (part of Type 3 Conditional)
• Will have: Future Perfect (action completed before a future point)

3. Verbs Followed by -ING (Gerunds)

Gerunds are verb forms ending in -ing that function as nouns. They are used in several contexts, often for actions that were completed or are ongoing.

1. After prepositions: e.g., I'm good at swimming.
2. After certain verbs:
   • like, love, hate, enjoy, miss, feel like, mind, finish, risk, practise, put off, stop, suggest, can't help, fancy, admit, deny, give up, imagine, keep (on), put off, spend time, can't stand, delay, regret, avoid, consider, involve, go on.
3. As the subject of a sentence: e.g., Reading is my favorite hobby.

4. Verbs Followed by to + Infinitive

Infinitives (to + base verb) are often used to express purpose, intention, or future actions.

1. To give a reason or answer the question “why”: e.g., I went to the store to buy milk.
2. After adjectives: e.g., It's easy to learn.
3. After certain verbs:
   • would like, want, need, decide, hope, arrange, expect, plan, forget, seem, appear, wish, promise, offer, refuse, learn, manage, afford, agree, fail, tend, happen, mean, prepare, pretend, threaten, attempt.

5. Reported Speech (Indirect Speech)

Reported speech is used to convey what someone else said without quoting them directly.

5.1. Verb Tense Changes

When reporting speech, verb tenses often shift back in time:

• Present Simple → Past Simple
• Present Continuous → Past Continuous
• Past Simple → Past Perfect Simple
• Present Perfect → Past Perfect Simple
• Will → Would
• Can → Could
• May → Might
• Must → Had to

5.2. Unchanged Tenses/Modals

Some tenses and modal verbs remain the same in reported speech:

• Conditional Simple: would + infinitive
• Past Perfect: had + past participle
• Past Perfect Continuous: had + been + V-ing
• Would / Could / Might / Had to

5.3. Changes in Time and Place Adverbs

Adverbs of time and place also change to reflect the new context:

• now → then
• today, tonight → that day, that night
• tomorrow → the next day / the following day
• yesterday → the previous day / the day before
• last night → the previous night / the night before
• next week, year → the following week / year
• a week ago → a week before
• here → there
• this, these → that, those
• my → his/her etc.

6. Conditionals

Conditional sentences express hypothetical situations and their consequences.

• Type 0 Conditional: General Truths

  Structure: If + Present Simple, Present Simple

  Example: If you heat water to 100 degrees Celsius, it boils.

• Type 1 Conditional: Real Possibilities

  Structure: If + Present Simple, Future Simple

  Example: If I don't finish my homework, I will stay home.

• Type 2 Conditional: Unreal Present/Future

  Structure: If + Past Simple, would + infinitive

  Example: If I saw a thief, I would hide in the wardrobe.

• Type 3 Conditional: Unreal Past

  Structure: If + Past Perfect, would have + past participle

  Example: If Tom had known her phone number, he would have called her.

7. Future Perfect Simple

Used to talk about an action that will be completed before a specific point in the future.

• Affirmative (A): Subject + will have + past participle + complements.
• Negative (N): Subject + won't have + past participle + complements.
• Interrogative (I): Will + subject + have + past participle + complements?

8. Future Continuous

Used to describe an action that will be in progress at a specific time in the future.

• Affirmative (A): Subject + will be + verb(-ing) + complements.
• Negative (N): Subject + won't be + verb(-ing) + complements.
• Interrogative (I): Will + subject + be + verb(-ing) + complements?

9. Passive Voice

The passive voice is used when the focus is on the action rather than the doer of the action.

• Present Simple: The car is washed every week.
• Present Continuous: The car is being washed at the moment.
• Past Simple: The car was washed yesterday.
• Past Continuous: The car was being washed yesterday at 10 o’clock.
• Present Perfect: The car has already been washed.
• Past Perfect: When I arrived, the car had already been washed.
• Future Simple (with "will"): The car will be washed tomorrow.
• Modal Verbs: The car should be washed this weekend.