CDS English · Vocabulary
Confusable word pairs: both halves must be right
Two words that sound or look alike, and four options that give a meaning to each. Only the option that gets both words right scores.
Why this matters
This is one of the most repeated formats in CDS English, and the pairs themselves repeat: compliment and complement, deify and defy, complaisant and complacent all came back in a later paper. The trick is always the same. An option gets one word right and the other wrong, or gives the right meanings to the wrong words.
Concept 1 of 5: Pin one word, then check the other: the pairs UPSC repeats
Every option makes two claims, one for each word. You need both claims true. So pin the word you know best, strike every option that gets it wrong, and only then look at the second word. Watch for the reversed pair: an option that uses both correct meanings but gives each to the wrong word.
Definition
The method:
- Pin the word you are surer of. Strike options with a wrong meaning for it.
- Among the survivors, check the second word.
- Reversed pair: if two options have the same two meanings in swapped places, decide which word owns which meaning. One of them is the answer.
- Near-miss meaning: 'defy = deny' and 'defy = oppose' differ by one idea. Choose the exact sense.
Pairs that have come back:
- Compliment / complement (2022 II, 2024 I): compliment = to praise; complement = to go well with, complete.
- Deify / defy (2022 II, 2024 I): deify = to treat as a god; defy = to oppose openly.
- Complaisant / complacent (2022 II, 2024 I): complaisant = eager to please; complacent = smugly over-confident.
- Climatic / climactic (2025 II, 2026 I): climatic = related to climate; climactic = of the most exciting point (the climax).
- Affect / effect (2026 I): affect = to influence (a verb); effect = the result (a noun).
Worked example
Persecute and Prosecute. (a) Persecute means to bring a legal case against, and prosecute means to treat cruelly. (b) Persecute means to treat someone cruelly for their beliefs, and prosecute means to bring a legal case against someone. (c) Persecute means to follow, and prosecute means to protect. (d) Persecute means to treat someone cruelly for their beliefs, and prosecute means to punish without trial.
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2024 · CDS (I) 2024 — English · Q91Moderate
Example 1 · Vocabulary · Confusable Word Pairs
Directions: option describing meaning of both words in the pair
Compliment and Complement
Half right is fully wrong
An option that gets one word perfectly right is the most tempting wrong answer. Never mark an option until you have checked its claim about both words.
The reversed pair
In the deify / defy items, one option gave 'confer the status of god' and 'oppose' but to the wrong words. Both meanings were familiar, so it felt right. Ask which word owns which meaning.
Close is not exact
'Defy = deny' sounds close to 'defy = oppose', but only oppose is right. 'Complacent = in the same place' is built only from the look of the word (place). Pick the sense a dictionary would give.
Concept 2 of 5: Sound-alike pairs: things, places and writing
These pairs differ by a letter or two and name different things: office paper and standing still, a lodger and a boundary, a poem and a speech. Learn each pair with one hook that ties the spelling to the meaning.
Definition
Hooks that work:
- Stationery has e for envelope; stationary has a for 'at a standstill'.
- A boarder pays for board (meals and lodging); a border is a boundary.
- An epitaph is on a tomb; an epithet describes a person (Alexander the Great).
- An elegy is a sad poem; a eulogy (eu = good + logos = words) praises the dead.
| Pair | First word means | Second word means | Sitting |
|---|---|---|---|
| Stationery / stationary | Writing and office material | Not moving, immobile | 2024 (I) |
| Boarder / border | A person paid for food and lodging | A boundary | 2024 (I) |
| Epitaph / epithet | Words written on a tombstone | A word or phrase naming a quality | 2024 (I) |
| Pontoon / platoon | A floating support for a temporary bridge | A small unit of soldiers | 2026 (I) |
| Elegy / eulogy | A sad poem of mourning | A speech or writing in praise of the dead | 2026 (II) |
| Cursor / cursory | The pointer on a screen | Done quickly, without care | 2026 (I) |
| Liable / libel | Legally responsible | Publishing something false that harms someone's name | 2026 (I) |
| Voyager / voyeur | A traveller | A person who enjoys watching the private lives of others | 2026 (II) |
Every pair keeps its sound and changes its meaning completely. Learn each pair as one unit.
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2024 · CDS (I) 2024 — English · Q93Moderate
Example 2 · Vocabulary · Confusable Word Pairs
Directions: option describing meaning of both words in the pair
Stationery and Stationary
Both meanings of one word
If an option gives the two words the same meaning, it is wrong. The pair exists because the words differ.
Elegy and eulogy
Both are about the dead. An elegy is a sad poem; a eulogy is praise, usually a speech at a funeral. The reversed option swaps them.
Platoon is not a bridge
A pontoon floats and holds up a temporary bridge (ponte = bridge). A platoon is a group of soldiers. Defence aspirants should never lose this one.
Concept 3 of 5: Sound-alike pairs: actions, states and qualities
These pairs name actions, states of mind or qualities. They often share most of their letters, and the wrong options borrow a meaning from a third word that sounds similar.
Definition
Hooks that work:
- Accept (take, agree to) vs except (leave out): ex = out.
- Conscious (awake, able to perceive) vs conscience (inner sense of right and wrong): science-like ending, moral sense.
- Differ (be different) vs defer (delay, or yield to someone's view).
- Hard (with effort, difficult) vs hardly (scarcely).
| Pair | First word means | Second word means | Sitting |
|---|---|---|---|
| Accept / except | To agree to, to take | To leave out, exclude | 2022 (II) |
| Discomfort / discomfit | Unease, mild pain | To embarrass, to upset someone's plans | 2024 (I) |
| Conscious / conscience | Awake and able to perceive | Inner sense of right and wrong | 2026 (I) |
| Hard / hardly | Difficult; with great effort | Scarcely, almost not | 2026 (I) |
| Differ / defer | To be different | To put off, delay | 2026 (II) |
| Flaunt / flinch | To show off | To shy away in pain or fear | 2026 (II) |
| Nefarious / nebulous | Wicked, criminal | Vague, indistinct | 2026 (II) Scandalous is close to nefarious: a nefarious act is wicked enough to cause scandal. When two options both fit nefarious, let the nebulous half decide. |
Check both halves: the option with the best-sounding first meaning can still fail on the second.
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2026 · CDS (I) 2026 — English · Q10Moderate
Example 3 · Vocabulary · Confusable Word Pairs
Directions: In the following items, a pair of words is provided. You are required to select the option that most appropriately describes the meaning of both the words and mark your response on the Answer Sheet accordingly.
Conscious and Conscience
Hardly is not 'very hard'
Hardly means scarcely: 'I hardly know him' = I know him very little. The option 'hardly = very difficult' turns it into a stronger form of hard, which it is not.
Discomfit is not discomfort
Discomfort is a feeling of unease. Discomfit is an action: to embarrass someone or upset their plans. Options that give discomfit 'unfit' are built from the sound alone.
Defer has a second sense
Defer also means to yield to someone out of respect (defer to an elder). Options that say 'defer = to be respectful' borrow this, but pair it with a wrong meaning of differ.
Concept 4 of 5: Prefix pairs: e-/ex- out, in-/im- in, re- back
Many pairs differ only in the prefix. If you know what each prefix does, you know which word goes which way: e- or ex- moves out, in- or im- moves in, re- goes back or undoes.
Definition
Prefixes to read:
- e-, ex- = out (emigrate = move out of a country; evoke = call out a feeling).
- in-, im- = in or on (immigrate = move into a country; invoke = call on).
- in-, im- can also mean not (incredible = not believable). Read the word to know which.
- re- = back or undo (revoke = call back, cancel).
The method:
- Give each prefix its direction.
- Join it to the shared root and pin one word.
- Check the second word as usual.
Pairs tested this way:
- 2022 (II): evoke (bring out a response) / invoke (call upon, appeal to); emigrate (leave a country) / immigrate (arrive in a country); immolate (sacrifice) / emulate (follow out of admiration).
- 2024 (I): enquiry (asking for information) / inquiry (a formal investigation).
- 2026 (I): invoke (use a law or power to achieve something) / revoke (officially cancel); imminent (about to happen) / eminent (famous and respected); incredible (hard to believe) / incredulous (unwilling to believe).
- 2026 (II): edify (improve someone's mind, uplift) / educe (draw out, extract).
Worked example
Explicit and Implicit. (a) Explicit means suggested but not stated, and implicit means clearly stated. (b) Explicit means clearly stated, and implicit means suggested but not stated directly. (c) Explicit means outside the law, and implicit means within the law. (d) Explicit means clearly stated, and implicit means completely false.
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2022 · CDS (II) 2022 — English · Q99Moderate
Example 4 · Vocabulary · Confusable Word Pairs
Directions: describe the meaning of a pair of similar words
'Emigrate' and 'Immigrate'
Im- does not always mean in
In imminent the im- is not 'into'. Learn it as a whole: imminent = about to happen (an imminent storm); eminent = famous and respected (an eminent scientist).
Incredible is about the thing, incredulous about the person
A story is incredible (hard to believe). The listener is incredulous (unwilling to believe it). An option that swaps them is a reversed pair.
Not every pair is a prefix pair
Immolate (to sacrifice, often by burning) and emulate (to copy someone you admire) only sound alike. They do not share a root. Treat such a pair as a sound-alike and learn both meanings.
Concept 5 of 5: Same root, different ending
Here both words share a root and differ only in the ending: masterful and masterly, presumptive and presumptuous. The ending changes the meaning, often from a neutral sense to a judgement on someone's behaviour.
Definition
Endings to watch:
- -ful often describes a person's manner (masterful = domineering); -ly often describes skill (masterly = very skilful).
- -ive often states a fact or likelihood (presumptive = likely, presumed); -uous often judges behaviour (presumptuous = too bold).
- -ious vs -uous: ingenious = clever and inventive; ingenuous = innocent, too trusting.
| Pair | First word means | Second word means | Sitting |
|---|---|---|---|
| Perspicacity / perspicuity | Sharpness of mind, ability to understand | Clearness of expression | 2022 (II) |
| Masterful / masterly | Domineering, imperious | Highly skilful | 2024 (I) |
| Sympathy / empathy | Feeling for someone in trouble | Understanding another's feelings as if they were your own | 2022 (II) The 2022 (II) item put it as: sympathy = sharing another's feelings, empathy = understanding them. |
| Reward / award | Something given in return for effort or service | A prize given in recognition, often formally | 2022 (II) |
| Concurrent / consecutive | Happening at the same time | Following one after another | 2024 (I) |
| Presumptive / presumptuous | Likely to be true, presumed (the heir presumptive) | Too bold, disrespectful | 2026 (II) |
| Tempestuous / temperamental | Stormy, violent in feeling | Moody, unpredictable | 2026 (II) |
| Ingenious / ingenuous | Clever and inventive | Innocent and too trusting | 2026 (II) |
| Concord / concourse | Agreement, harmony | A large open hall where people gather (a station concourse) | 2026 (II) |
The ending carries the difference. Read it before you read the options.
Practice this conceptself-check · 4 quick reps
The same idea in a real exam question:
CDS · 2026 · CDS (II) 2026 — English · Q1Easy
Example 5 · Vocabulary · Confusable Word Pairs
Directions: In the following items, a pair of words is provided. You are required to select the option that most appropriately describes the meaning of both the words and mark your response on the Answer Sheet accordingly.
Presumptive and Presumptuous
Masterful is not 'full of mastery'
Masterful describes a commanding, domineering manner. Masterly describes great skill (a masterly performance). The ending does not mean what it seems to.
Concurrent and consecutive in law
Two sentences served concurrently run at the same time; served consecutively, one starts after the other ends. The options swap these to catch quick readers.
Ingenuous is not genius
Ingenious has the 'genius' sound and means clever. Ingenuous means innocent and too trusting, like a child. Options that call ingenuous 'genuine' or 'inventive' are wrong.
Summary — formulas & gotchas at a glance
A revision cheat-sheet for the formulas and gotchas above. Click any concept name to jump back to its full explanation.
Reference tables (3)
Sound-alike pairs: things, places and writing8 rows
| Pair | First word means | Second word means | Sitting |
|---|---|---|---|
| Stationery / stationary | Writing and office material | Not moving, immobile | 2024 (I) |
| Boarder / border | A person paid for food and lodging | A boundary | 2024 (I) |
| Epitaph / epithet | Words written on a tombstone | A word or phrase naming a quality | 2024 (I) |
| Pontoon / platoon | A floating support for a temporary bridge | A small unit of soldiers | 2026 (I) |
| Elegy / eulogy | A sad poem of mourning | A speech or writing in praise of the dead | 2026 (II) |
| Cursor / cursory | The pointer on a screen | Done quickly, without care | 2026 (I) |
| Liable / libel | Legally responsible | Publishing something false that harms someone's name | 2026 (I) |
| Voyager / voyeur | A traveller | A person who enjoys watching the private lives of others | 2026 (II) |
Every pair keeps its sound and changes its meaning completely. Learn each pair as one unit.
Sound-alike pairs: actions, states and qualities7 rows
| Pair | First word means | Second word means | Sitting |
|---|---|---|---|
| Accept / except | To agree to, to take | To leave out, exclude | 2022 (II) |
| Discomfort / discomfit | Unease, mild pain | To embarrass, to upset someone's plans | 2024 (I) |
| Conscious / conscience | Awake and able to perceive | Inner sense of right and wrong | 2026 (I) |
| Hard / hardly | Difficult; with great effort | Scarcely, almost not | 2026 (I) |
| Differ / defer | To be different | To put off, delay | 2026 (II) |
| Flaunt / flinch | To show off | To shy away in pain or fear | 2026 (II) |
| Nefarious / nebulous | Wicked, criminal | Vague, indistinct | 2026 (II) Scandalous is close to nefarious: a nefarious act is wicked enough to cause scandal. When two options both fit nefarious, let the nebulous half decide. |
Check both halves: the option with the best-sounding first meaning can still fail on the second.
Same root, different ending9 rows
| Pair | First word means | Second word means | Sitting |
|---|---|---|---|
| Perspicacity / perspicuity | Sharpness of mind, ability to understand | Clearness of expression | 2022 (II) |
| Masterful / masterly | Domineering, imperious | Highly skilful | 2024 (I) |
| Sympathy / empathy | Feeling for someone in trouble | Understanding another's feelings as if they were your own | 2022 (II) The 2022 (II) item put it as: sympathy = sharing another's feelings, empathy = understanding them. |
| Reward / award | Something given in return for effort or service | A prize given in recognition, often formally | 2022 (II) |
| Concurrent / consecutive | Happening at the same time | Following one after another | 2024 (I) |
| Presumptive / presumptuous | Likely to be true, presumed (the heir presumptive) | Too bold, disrespectful | 2026 (II) |
| Tempestuous / temperamental | Stormy, violent in feeling | Moody, unpredictable | 2026 (II) |
| Ingenious / ingenuous | Clever and inventive | Innocent and too trusting | 2026 (II) |
| Concord / concourse | Agreement, harmony | A large open hall where people gather (a station concourse) | 2026 (II) |
The ending carries the difference. Read it before you read the options.
Watch out for (15)
- Half right is fully wrong→ Pin one word, then check the other: the pairs UPSC repeats
- The reversed pair→ Pin one word, then check the other: the pairs UPSC repeats
- Close is not exact→ Pin one word, then check the other: the pairs UPSC repeats
- Both meanings of one word→ Sound-alike pairs: things, places and writing
- Elegy and eulogy→ Sound-alike pairs: things, places and writing
- Platoon is not a bridge→ Sound-alike pairs: things, places and writing
- Hardly is not 'very hard'→ Sound-alike pairs: actions, states and qualities
- Discomfit is not discomfort→ Sound-alike pairs: actions, states and qualities
- Defer has a second sense→ Sound-alike pairs: actions, states and qualities
- Im- does not always mean in→ Prefix pairs: e-/ex- out, in-/im- in, re- back
- Incredible is about the thing, incredulous about the person→ Prefix pairs: e-/ex- out, in-/im- in, re- back
- Not every pair is a prefix pair→ Prefix pairs: e-/ex- out, in-/im- in, re- back
- Masterful is not 'full of mastery'→ Same root, different ending
- Concurrent and consecutive in law→ Same root, different ending
- Ingenuous is not genius→ Same root, different ending
Test yourself on Vocabulary
20 past CDS questions from this chapter, timed at 20 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.