English Grammar

120 Grammar Rules — Part 3: Prepositions, Articles & Common Confusions (Rules 49 × 72)

18 min read Omprakash Maury March 2026

Part 3 of our 5-part grammar series covers Rules 49 to 72 — focusing on possessives, articles (a/an/the), prepositions (in, on, at, with, by, into), infinitives, question tags, antecedent rules, and plural noun confusions.

📘 Why Prepositions & Articles are Exam Goldmines

In every Bank (IBPS, SBI), SSC (CGL, CHSL), and Railway (NTPC, Group D) exam, the English section is a make-or-break battleground. Students often lose 5–8 marks simply because they confuse a with an, or write angry at instead of angry with. These are not just grammar technicalities — they are direct question types that appear in:

✅ Error Spotting — Find the grammatical error in the underlined part
✅ Fill in the Blanks — Choose the correct preposition or article
✅ Sentence Correction — Rearrange or correct the sentence
✅ Cloze Test — A paragraph with blanks testing vocabulary + grammar

The rules in this part are high-frequency — they appear in almost every competitive exam paper from the last 10 years. Master them once, and you'll save precious time during the exam by spotting errors instantly without re-reading the sentence multiple times.

📌 Quick Navigation — Rules in this Part:

Rule 49: Common vs Split Possession

Common Possession (one item shared): Possessive sign on the last noun only.

Split Possession (each owns separately): Possessive sign on each noun + plural noun.

? Ram and Shyam's car is being decorated. (one shared car)
? Ram's and Shyam's cars are being decorated. (separate cars — plural "cars")
? Ram's and Shyam's car is being decorated. (split possession needs plural noun)

            Rule 50: "It's" vs "Its"
            "It's" = It is
"Its" = Possession (no apostrophe)

            ? The child is carrying it's book.
? The child is carrying its book.
? Its called a miracle.
? It's called a miracle.

        

            Rule 51: "A Number of" vs "The Number of"
            A number of + plural noun + plural verb
The number of + plural noun + singular verb

            ? A number of students are waiting here.
? The number of students is fifty.
? A number of tickets were sold almost immediately.

        

Rule 52: "It is Time" / "It is High Time"

No subject: followed by "to + V1". With subject: followed by V2 (past tense).

? It is time to work hard. (no subject)
? It is time he worked hard. (subject "he" ? past tense)
? It is time we went home. (subject "we" ? past tense)

            Rule 53: "Angry with" (person) vs "Angry at" (thing)
            "Angry with" ? for a person or living thing
"Angry at" ? for a thing or situation

            ? I am angry with Shyam because he did not go to class.
? The residents were angry at the lack of parking spaces.

        

Rule 54: "Know" Needs How/When/Where/Why Before "To"

"Know" is NOT directly followed by "to". Use how, when, where, why, what first.

? I don't know to make tea.
? I don't know how to make tea.
? Do you know where the Post Office is?

            Rule 55: "Else-But" & "Other/Rather²Than"
            "Else" ? always followed by "but"
"Other" / "Rather" ? always followed by "than"

            ? It is nothing else but mere foolishness.
? He met no other person than Ram.
? I would rather stay at home than go out.

        

            Rule 56: "Sort/Type/Kind" Always Followed by Singular Verb
            ? This type of articles is sold in the market.
? This sort of camera is very expensive.
? Any kind of racism is abhorrent to me.

        

            Rule 57: Prepositions — "In" vs "Inside" vs "Into"
            
                
                    Preposition
                    Implies
                    Example
                
InStatic (already inside)I am in the class.
InsideMovement (outside ? inside)I came inside the class.
IntoComing toward / change of stateCome into the house.

            ? He threw the letter into the fire.
? The fruit can be made into jam. (change of state)
? I know my husband inside out. (= completely)

        

Preposition	Implies	Example
In	Static (already inside)	I am in the class.
Inside	Movement (outside ? inside)	I came inside the class.
Into	Coming toward / change of state	Come into the house.

            Rule 58: "With" (non-living) vs "By" (living)
            ? We write with a pen. (pen = non-living)
? He hit the dog with a stick. (stick = non-living)
? The book was translated by a well-known author. (author = living)
? What is the time by your watch? (exception — "by" with watch for time)

        

            Rule 59: Don't Use "From" with "Start"
            ? My exams start from Monday.
? My exams start on Monday.
? He will prepare for the exams from Monday. (no "start" — OK)

        

Rule 60: Special Gerund Forms — "To + V1+ing"

These phrases always take "to + V1+ing" (not "to + V1"):

be + used + to + V1+ing
accustomed to + V1+ing
addicted to + V1+ing
with a view to + V1+ing
look forward to + V1+ing
prone to + V1+ing
devoted to + V1+ing
in addition to + V1+ing

? I look forward to hearing from you.
? I am not accustomed to being treated like this.
? Measures taken with a view to increasing profits.

Rule 61: Articles "A" vs "An" — Based on Sound, Not Spelling

Consonant sound ? "a". Vowel sound ? "an".

? An NCC cadet. (N = vowel sound "en")
? A university. (U = consonant sound "yu")
? An umbrella. (U = vowel sound)
? A European university. (E = consonant sound "yu")
? A one-rupee note. (O = consonant sound "wa")
? A year. (Y/W always take "a")

Rules 62 & 63: When to Use & Omit Article "The"

USE "The" before:

Mountain ranges (The Himalayas), Deserts (The Sahara), Rivers (The Nile)
Oceans/Seas (The Pacific), Newspapers (The Times of India)
Abbreviated countries (The USA, The UK, The UAE)
Superlative degree (The best book), Musical instruments (The Guitar)
Unique things (The moon, The sun, The earth)
Government organizations

DO NOT use "The" before:

Cities (Delhi, Sydney), Countries (India, France)
Continents (Asia, Europe), Streets (George Street)
Mountain peaks (Mount Everest — NOT "The Mount Everest")
Single lakes (Lake Eyre), Single islands (Easter Island)
Languages (English, Spanish), Sports (cricket, football)

Rule 64: "The + Adjective" = Whole Group

When "the" is used before an adjective, it means the entire group (plural noun).

? The poor are not always dishonest. (= poor people)
? The honest are respected. (= honest people)
? The brave deserve the fair. (= brave people)

            Rule 65: Same Noun Connected by Preposition — Singular Form
            ? Villages after villages were destroyed.
? Village after village was destroyed.
? Book after book had been read by him.
? Page after page was reviewed.

        

Rule 66: Important Irregular Plurals

Singular	Plural	Singular	Plural
Man	Men	Mouse	Mice
Foot	Feet	Tooth	Teeth
Goose	Geese	Louse	Lice
Son-in-law	Sons-in-law	Passer-by	Passers-by

Compound noun possession: Use apostrophe ('s) at the end:

? Sister-in-law's car.

            Rule 67: "Male/Female" (characteristics) vs "Man/Woman" (profession)
            "Female doctor" = doctor for females
"Woman doctor" = the doctor is a woman

            ? She went to a female doctor. (for females)
? Raj went to a female doctor to get himself treated.
? Raj went to a woman doctor to get himself treated.

        

Rule 68: Antecedent Rule

The noun/pronoun before a relative pronoun = Antecedent. Without antecedent, use whoever/whomever.

? Ram met him who they say has helped us. (antecedent = "him")
? Ram met whoever they say has helped us. (no antecedent)
? He saw her whom everyone admires. (antecedent = "her")
? He saw whomever everyone admires. (no antecedent)

Rules 69 × 72: Question Tags

Rule 69: Positive statement ? negative tag. Negative statement ? positive tag.

? He has worked hard, hasn't he?
? He has not worked hard, has he?

Rule 70: "I am" ? tag is "aren't I" (not "amn't I").

? I am working hard, amn't I?
? I am working hard, aren't I?

Rule 71: Words like seldom, barely, hardly, scarcely, never have negative meaning ? use positive tag.

? He seldom comes, does he?
? I never realized that, did I?

Rule 72: Question tag must be in the same tense as the main statement.

? I am doing the work, don't I? (tense mismatch)
? I am doing the work, aren't I?

🚨 Most Common Mistakes Students Make (Rules 49–72)

Based on analysis of thousands of previous year questions, here are the most frequent errors students make in this section — and how to avoid them instantly:

❌ Mistake 1: Writing "It's tail was wagging." (should be "Its tail")
✅ Fix: If you can replace with "it is", use It's. If you can't, use Its.

❌ Mistake 2: Writing "A number of students was absent."
✅ Fix: A number of = many → always plural verb. The number of = a count → always singular.

❌ Mistake 3: Writing "I don't know to cook."
✅ Fix: "Know" always needs how/when/where/why/what before infinitive. Say "I don't know how to cook."

❌ Mistake 4: Writing "An university student"
✅ Fix: "University" starts with a consonant sound /ju/ → use A. Rule: it's about the sound, not the spelling.

❌ Mistake 5: Writing "Village after villages was destroyed."
✅ Fix: When the same noun is repeated with a preposition → use singular form both times. "Village after village was destroyed."

🎯 Exam Strategy: How to Attempt Grammar Questions in 10 Seconds

Top scorers in Bank and SSC exams don't re-read sentences 3–4 times. They use a systematic 3-step approach to eliminate wrong options in under 10 seconds:

Step 1 — Identify the grammar area: Is this a question about preposition, article, tense, or subject-verb agreement? The moment you identify the category, half the rules become irrelevant.
Step 2 — Apply your rule: Pull the specific rule from memory (e.g., "angry with = person, angry at = thing"). No guessing — just rule application.
Step 3 — Cross-check with elimination: If two options look similar, test both in the sentence mentally. The one that "sounds wrong" to your trained ear (after enough practice) is almost certainly the error.

💡 Pro Tip: For Error Spotting questions, always check the verb first (singular/plural?), then prepositions, then articles. This order catches 80% of all errors in under 15 seconds.

📋 Quick Revision Table: Key Rules at a Glance

Use this table the night before your exam to quickly revise all 24 rules from this part in under 5 minutes:

Rule	Key Concept	Remember
49	Common vs Split Possession	Shared = 's on last noun only
50	It's vs Its	It is = It's \| Possession = Its
51	A number of vs The number of	A = plural verb \| The = singular
52	It is time	No subject = to+V1 \| With subject = V2
53	Angry with/at	With = person \| At = thing/situation
54	Know + infinitive	Always: know + how/when/where + to
55	Else-But \| Other/Rather-Than	Else → but \| Other/Rather → than
56	Sort/Type/Kind	Always singular verb
57	In/Inside/Into	In=static \| Inside=entry \| Into=movement/change
58	With vs By	With = tool \| By = living agent
59	Start + From	Never "start from" — use "start on"
60	Special Gerund phrases	"look forward to" → always + V-ing
61	A vs An	Based on sound — not spelling
62–63	Use & Omit "The"	Rivers/ranges/oceans → The \| Cities/sports/languages → no The
64	The + Adjective	Refers to entire group (plural sense)
65	Same noun + preposition	Always singular: "day after day"
66	Irregular Plurals	Goose→Geese, Son-in-law→Sons-in-law
67	Male/Female vs Man/Woman	Female = doctor for women \| Woman = female doctor
68	Antecedent Rule	No antecedent → use whoever/whomever
69–72	Question Tags	Positive → negative tag \| "I am" → aren't I