Assistant Provident Fund Commissioner and Enforcement Officer / Accounts Officer (APFC and EO/AO) 2025 recruitment test. Transcribed from the Commission's own booklet (series A, PENA-A-PTS); answer worked out by our faculty — UPSC has published no answer key for this sitting. This question is in Part A. Answer last reviewed 25 August 2026.

They _________ be very far away. I saw them a little while ago.

(a)shall not
(b)cannot
(c)should not
(d)ought not

Answer

Why

Correct — B, (b) cannot.

The second sentence is doing the work: 'I saw them a little while ago.' That is evidence, and the first sentence is the conclusion the speaker draws from it. The item is therefore about deduction, and specifically about negative deduction - the modal that says a thing is impossible in the light of what is known.

English assigns that job to 'cannot'. Where 'must' expresses the positive deduction ('They must be nearby - I saw them a moment ago'), 'cannot' expresses its negative counterpart ('They cannot be far away'). The pair is fixed: the negative of deductive 'must' is not 'must not' but 'cannot'. If someone was seen a few minutes ago, it is not merely undesirable or unwise that they should be far away - it is impossible, given how far a person can travel in a few minutes. That is exactly the force 'cannot' carries.

The other three options are modals of obligation and advice. 'Should not' and 'ought not' say that something is inadvisable or wrong; 'shall not' issues a prohibition or a commitment. All three would turn the sentence into a judgement about how far away the people are permitted or advised to be, which makes no sense beside a sentence reporting that they were seen a little while ago - the speaker is not laying down a rule for their movements, but working out where they must be.

A reader can also confirm the answer by reversing it. Turn the deduction positive and the sentence becomes 'They must be quite close - I saw them a little while ago', which is plainly the intended sense. The modal that negates that 'must' is 'cannot'.

Why the others are wrong

(a)shall not — 'Shall not' is the modal of prohibition and undertaking - the form that fills statutes and formal commitments: no employer shall deduct, thou shalt not steal. Substituted here it reads as an instruction forbidding the people from being far away, which is not something a rule can forbid and not something the speaker is in a position to prohibit. There is also no addressee to prohibit: the subject is 'they', reported in the third person, and the speaker is reasoning about them rather than issuing directions to them.
(c)should not — 'Should not' expresses advice or expectation about what is proper. It has a probability sense as well - 'they should be there by now' means they are expected to be - but that sense runs the wrong way here. 'They should not be very far away' would say either that it is inadvisable for them to be far away, which is a judgement nobody is making, or that they are not expected to be, which is a weaker claim than the evidence licenses. Having seen someone minutes earlier does not make their being distant merely unexpected; it makes it impossible. Choosing 'should not' understates the strength of the inference the second sentence supports.
(d)ought not — 'Ought not' is the near-twin of 'should not' - a modal of moral obligation or advisability, slightly more formal and slightly more emphatic about duty. It fails for the same reason, and rather more sharply: 'ought' carries a stronger flavour of what is right or fitting, so 'they ought not be very far away' reads as a statement about how far it is proper for them to have gone. The sentence contains no question of propriety at all. It also leaves the second sentence stranded, since being seen a little while ago is evidence about distance and not a reason why someone ought to behave in a particular way.

Concept

English modals do two quite different jobs, and objective papers test whether a candidate can tell which job a sentence needs.

The first is deontic: obligation, permission, prohibition and advice. Must, shall, should, ought to, may and can all appear here - you must file the return, you shall not deduct, you should apply early, you may leave.

The second is epistemic: the speaker's assessment of how likely something is, given the evidence. Must, may, might, could and can appear here too, but with different meanings - she must be at home, she may be at home, she might be at home.

Deduction is the strong end of the epistemic scale, and its two poles are asymmetric in a way worth memorising. The positive is 'must': 'He must be the new clerk.' The negative is 'cannot', not 'must not': 'He cannot be the new clerk.' 'Must not' has been taken over by prohibition, which is why English reaches for 'cannot' to say that something is ruled out by the evidence.

The way to identify a deduction item is to look for the evidence sentence. Deduction rarely stands alone; it comes with a reason, either in a neighbouring sentence or in a clause introduced by 'because', 'since' or a dash. Here the evidence is 'I saw them a little while ago', and the moment the evidence is identified, the option list resolves into one modal that reasons and three that instruct.

This closes the fill-in-the-blank set, and it completes the set's tour of the modal system: general possibility, deliberative suggestion, and now negative deduction. Three of the five items in the set turn on modals, which is a fair measure of how central modality is to EPFO's English testing.

The option list is homogeneous in a particular way - all four are negated modals - so nothing can be eliminated by shape. What separates them is function, and the sentence supplies the function through its second half. This is the third item in the set whose answer lies outside the immediate neighbourhood of the blank, and the pattern is worth generalising: in a two-sentence stem, the unblanked sentence is almost always the evidence for the blank.

One small printing detail is worth noting because it can distract. The correct option is printed as the single closed-up word 'cannot' while the other three are two words each. That is standard for this modal - 'cannot' is normally written solid in a way that 'shall not' and 'should not' are not - and it is a feature of English spelling rather than a hint about the answer.

Key facts

The negative of deductive 'must' is 'cannot', not 'must not': 'He must be at home' negates to 'He cannot be at home', because 'must not' has been taken over by prohibition.
Deduction sentences almost always come with their evidence attached, in a neighbouring sentence or a because-clause; here the evidence is 'I saw them a little while ago'.
'Should not' and 'ought not' express advisability or expectation, which is a weaker claim than the evidence in this item licenses - being seen minutes ago makes distance impossible, not merely unexpected.
'Shall not' is the modal of prohibition and formal undertaking, and it requires someone with authority to prohibit and, usually, an addressee - neither of which this sentence has.
Modals work on two planes at once: deontic, about obligation and permission, and epistemic, about likelihood; the same modal can appear on both, so the sentence must be read for which plane is in play.

Study next

Modals of deduction across positive and negative: must, cannot, may, might, could, and the asymmetry between must not and cannot.Deontic against epistemic uses of the same modal, and how context selects between them.Perfect modals for deduction about the past: must have been, cannot have been, might have been.Should and ought to in their probability sense - 'the train should be here by now' - and how that differs from advice.Reading a two-sentence stem as claim plus evidence, and using the evidence to fix the modal.

Common traps

Reaching for 'must not' as the negative of deductive 'must'; English uses 'cannot' for that job and reserves 'must not' for prohibition.
Choosing 'should not' because it sounds hedged and therefore safe; it understates an inference the evidence makes certain.
Ignoring the second sentence, which is the only thing in the item that identifies it as a deduction at all.
Reading 'ought not' as interchangeable with 'cannot'; it belongs to the obligation family, where nothing in this sentence is at issue.
Being influenced by the printing - 'cannot' is set as one word while the others are two - which is a spelling convention and not a signal.

Across EPFO's English sections the modal items are set on the functions that everyday speech uses loosely: deduction, deliberation, general possibility, and obligation of differing strengths. Because every option in such a set is a modal, the discrimination has to be functional, and the papers reliably supply the function somewhere in the stem - an evidence clause for deduction, a first-person plural subject for deliberation, a frequency adverbial for general possibility. The preparation that works is to hold a small table of functions against modals and to practise identifying the function from the stem before looking at the options at all. That single habit covers three of the five items in this paper's fill-in-the-blank set.

Related PYQs

EPFO_EOAO_2017_Q8

Which one of the following parts of the sentence, “After a lot of argument I brought him forward to my point of view”, has an error?

(a) After a lot of argument
(b) I brought him forward
(c) to my point of view
(d) No error

Answer(b) I brought him forward

Error-spotting where the fault is in the verb phrase rather than the vocabulary, requiring the same judgement about which construction English actually uses.

EPFO_APFC_2016_Q7

Consider the sentence : 'The teacher gave me the book'. 1 2 3 4 5 6 where the words are numbered for convenience of reference. Consider also the insertion of a single word 'only' into this sentence to indicate a desired emphasis. Where shall this word be inserted if the emphasis is to be (i) On the recipient (ii) On the uniqueness of the item given (iii) On the giver respectively (only one at a time) ?

(a) (i) Between 3-4; (ii) After 6; (iii) Between 2-3
(b) (i) Between 3-4; (ii) Between 5-6; (iii) Before 1
(c) (i) Between 4-5; (ii) Between 3-4; (iii) After 1
(d) (i) Between 2-3; (ii) Between 4-5; (iii) Between 1-2

Answer(b) (i) Between 3-4; (ii) Between 5-6; (iii) Before 1

Tests where a word may be inserted into a numbered sentence - structural reasoning about a frame, in the way a modal item reasons about function.

EPFO_EOAO_2017_Q7

Which one of the following parts of the sentence, “As you know that the ignorant are easily duped”, has an error?

(a) As you know
(b) that the ignorant
(c) are easily duped
(d) No error

Answer(b) that the ignorant

An error item turning on a single function word, the same scale of decision as choosing between four negated modals.

Practice

practice — not a real PYQ
That ______ be the Accounts Officer at the counter. She is on leave this week.
- (a)must not
- (b)cannot
- (c)should not
- (d)need not
Answer(b) cannot - the second sentence is evidence, and the first draws a negative deduction from it. 'Must not' would prohibit rather than deduce, 'should not' would advise or merely lower the expectation, and 'need not' would deny a necessity rather than a possibility.
practice — not a real PYQ
Which one of the following sentences expresses a deduction rather than an obligation ?
- (a)Applicants must enclose a copy of the Aadhaar card
- (b)You must not smoke inside the building
- (c)He must be the officer they were expecting
- (d)We must reach the venue before ten
Answer(c) He must be the officer they were expecting - here 'must' states what the speaker concludes from the evidence. The other three impose a requirement, a prohibition or a necessity on someone's conduct.

Why