Concept
A preposition is a word placed before a noun or pronoun to show its relationship with another word in the sentence. Prepositions indicate time, place, direction, cause, and manner. In BCS exams, prepositions are one of the most frequently tested grammar topics — especially fixed prepositional phrases and confusing pairs.
The key challenge: there are very few "rules" for prepositions. Most usage is idiomatic — you simply have to memorize the correct preposition that goes with each word. That said, time and place prepositions do follow logical patterns.
Key Rules
Time Prepositions
| Preposition |
When to Use |
Examples |
| at |
Exact time, festivals, night |
at 5 PM, at noon, at midnight, at night, at dawn, at Eid, at Christmas |
| on |
Days, dates, specific day parts |
on Monday, on 21 March, on Eid day, on Friday morning |
| in |
Months, years, seasons, general parts of day |
in January, in 2026, in summer, in the morning, in the evening |
| by |
Deadline (before or at that time) |
by 5 PM, by next week, by the end of March |
| since |
Point of time (with perfect tense) |
since 2010, since Monday, since morning, since independence |
| for |
Duration / period of time |
for 5 years, for 3 hours, for a long time |
Memory Trick: Think of time as a funnel — in (big: months/years) > on (medium: days) > at (small: exact time).
BCS Trap: "at night" but "in the morning/afternoon/evening" — night is the exception!
Place Prepositions
| Preposition |
When to Use |
Examples |
| at |
Specific point or location |
at the door, at home, at the bus stop, at school |
| on |
Surface or line |
on the table, on the wall, on the floor, on the road |
| in |
Enclosed space or area |
in the room, in Dhaka, in Bangladesh, in the box |
| between |
Two things/people |
between you and me, between Dhaka and Chittagong |
| among |
More than two |
among the students, among all the candidates |
BCS Most Tested — Fixed Prepositions
These are the gold-standard BCS preposition questions. Memorize every single one:
The "TO not THAN" Group (BCS Favorite):
- senior to (NOT senior than)
- junior to (NOT junior than)
- prefer to (NOT prefer than)
- prior to (NOT prior than)
- superior to (NOT superior than)
- inferior to (NOT inferior than)
- anterior to, posterior to
Die of vs Die from:
- die of disease/hunger/thirst — "He died of cholera"
- die from wound/injury/external cause — "He died from a stab wound"
Agree with vs Agree to:
- agree with a person — "I agree with you"
- agree to a proposal/plan — "I agree to your proposal"
Angry with vs Angry at:
- angry with a person — "She is angry with her brother"
- angry at a thing/situation — "She is angry at the decision"
Other Essential Fixed Prepositions:
- good at (something)
- interested in (something)
- depend on / rely on
- different from (NOT different than)
- similar to
- married to (NOT married with)
- congratulate on (an achievement)
- accuse of (a crime)
- charge with (a crime)
- consist of (parts)
- abstain from (something)
- apologize to (a person) for (something)
- prevent from
- refrain from
- succeed in
- insist on
- object to
- concerned about (worried) vs concerned with (involved in)
BCS Shortcuts
- "TO not THAN" rule: Whenever you see senior, junior, prefer, prior, superior, inferior, anterior, posterior — the answer is always to. If "than" appears as an option, it is WRONG.
- Since vs For: "Since" = point (since 2010). "For" = period (for 5 years). If the sentence uses present perfect/present perfect continuous, check which one fits.
- Between vs Among: Count the items. Two = between. Three or more = among. No exceptions in BCS.
- Die of/from: Disease = of. Wound/external = from. Think: disease is organic (of), wound is forced (from).
- Different FROM: Always "from" in formal/BCS English. Never "than" or "to".
Solved Examples (5 BCS-style MCQ)
Q1. He is senior ___ me by five years.
- (a) than (b) to (c) from (d) of
- Answer: (b) to
- Explanation: Senior/junior/superior/inferior always take "to", never "than". This is a Latin-origin comparative that does not follow the regular "than" pattern.
Q2. She has been living in Dhaka ___ 2015.
- (a) for (b) from (c) since (d) by
- Answer: (c) since
- Explanation: 2015 is a specific point in time, so we use "since". If it were "10 years" (a period), we would use "for". The present perfect continuous tense confirms this.
Q3. The old man died ___ cancer.
- (a) from (b) by (c) of (d) with
- Answer: (c) of
- Explanation: "Die of" is used for diseases (cancer, cholera, fever). "Die from" is used for wounds or external injuries.
Q4. I cannot agree ___ your proposal.
- (a) with (b) to (c) on (d) for
- Answer: (b) to
- Explanation: "Agree with" is used for a person. "Agree to" is used for a proposal, plan, or suggestion. Here, "proposal" is the object, so "to" is correct.
Q5. His answer is different ___ mine.
- (a) than (b) to (c) with (d) from
- Answer: (d) from
- Explanation: In standard/formal English (and BCS), "different" is always followed by "from", not "than" or "to".
Common Mistakes — Watch Out!
- "Senior than" is ALWAYS wrong. This is the single most repeated preposition error in BCS. Senior, junior, prefer, prior, superior, inferior — all take "to".
- "Married with" is wrong. The correct form is "married to". "She is married to a doctor."
- Confusing "since" and "for": Since Monday (point) vs For three days (period). If you see a number + time unit, it is "for".
- "Consist of" has no passive. You cannot say "is consisted of" — it is always "consists of" (active voice only).
- "Different than": While acceptable in American informal speech, BCS always marks "different from" as correct.
Question Pattern Recognition
Pattern 1 — "Fill in the blank with the correct preposition":
Look at the word BEFORE the blank. If it is senior/junior/prefer/superior/inferior → answer is "to".
Pattern 2 — "Identify the error":
Scan for "than" after senior/junior/prefer/prior. Scan for "different than", "married with", "return back to".
Pattern 3 — "Since vs For":
Check the object after the blank. Specific time (1990, Monday, morning) → since. Duration (5 years, 3 hours) → for.
Pattern 4 — "Die of vs Die from":
Check what caused the death. If it is a disease name → of. If it is a wound or accident → from.
Pattern 5 — "Between vs Among":
Count the entities. Two = between. More than two = among. BCS loves this in sentence correction questions.