SOF IEO flashcards

31 cards. Read the term and the definition here. The deck at the top of this page is optional.

Adverb of frequency position

Placed before the main verb but after the verb 'be'. Correct: 'She always arrives early' and 'She is always early'. Incorrect: 'She arrives always early'.

Negative adverbial inversion

When a clause opens with a negative or restrictive adverbial such as never, rarely, seldom, not only, subject and auxiliary swap: 'Rarely does he complain'.

Second conditional form

If + past simple, then would + base verb. It describes an unreal or unlikely present or future situation: 'If I had more time, I would travel'.

Third conditional meaning

If + past perfect, would have + past participle. It describes an imagined past that did not happen, often with regret: 'If she had left earlier, she would have caught it'.

Zero conditional use

Both clauses take the present simple. It states general truths, scientific facts and automatic results: 'If you heat ice, it melts'.

Mixed conditional pattern

Combines a third-conditional if-clause with a second-conditional result. It links a past cause to a present consequence: 'If I had saved money, I would be free now'.

Must versus have to

'Must' signals obligation felt by the speaker or strong logical certainty. 'Have to' signals obligation imposed by an outside rule or circumstance.

Mustn't versus needn't

'Mustn't' means something is prohibited. 'Needn't' means it is not necessary and you are free not to do it. The two are never interchangeable.

Modal perfect for deduction

Modal + have + past participle judges the past. 'Must have' means near certainty, 'can't have' means impossibility, 'might have' means possibility.

Should have done

Expresses an unfulfilled duty, criticism or regret about the past: 'You should have told me' means you did not tell me and that was wrong.

Collocation definition

A habitual word partnership that native usage fixes, such as 'make a decision', 'take responsibility', 'pay attention' or 'heavy rain'.

Separable phrasal verb

A two-part verb whose object may sit between verb and particle: 'turn the light off' or 'turn off the light'. Pronouns must go in the middle.

Inseparable phrasal verb

The object cannot split the verb and particle: 'look after the baby', never 'look the baby after'. Three-part verbs such as 'put up with' are always inseparable.

Idiom: bite the bullet

To force yourself to endure something painful or unpleasant that cannot be avoided, accepting the difficulty and getting on with it.

Idiom: a blessing in disguise

An apparent misfortune or setback that turns out to bring an unexpected benefit, so the bad event proves fortunate in the end.

Indirect question word order

After a polite opener such as 'Could you tell me', the clause keeps statement order with no auxiliary inversion: 'where the station is', not 'where is the station'.

Hedging for politeness

Softening a request or claim with cautious wording such as 'I was wondering whether', 'perhaps', 'it seems' or 'might', which lowers imposition and sounds more formal.

Combined work rate

Rates add when workers cooperate: 1/a + 1/b = 1/t. If one takes 6 hours and another 3, together they finish in 2 hours.

Successive percentage changes

Multiply the decimal multipliers rather than adding the percentages. A 20% rise then a 20% fall gives 1.2 × 0.8 = 0.96, a net 4% loss.

Average speed rule

Average speed equals total distance divided by total time, never the arithmetic mean of the speeds. Equal distances at speeds a and b give 2ab/(a+b).

Alligation mixture ratio

Mixing solutions of p% and q% to obtain r% requires amounts in the ratio (q − r) to (r − p). This cross-method solves most mixture problems.

Contrapositive equivalence

'If P then Q' is logically equivalent to 'If not Q then not P'. The converse and the inverse are not equivalent and are common distractor options.

Negating a universal claim

The negation of 'all A are B' is 'some A are not B'. A single counterexample is sufficient to disprove a statement of the form 'all' or 'every'.

Converse error

Assuming 'If Q then P' follows from 'If P then Q'. Valid reasoning never reverses a conditional without independent evidence for the reverse direction.

Unstated assumption

The hidden premise an argument needs so its evidence genuinely supports the conclusion. It is neither stated evidence nor a restatement of the conclusion.

Block notation in puzzles

Encode 'A is immediately left of B' as one rigid block AB. This collapses two slots into one and sharply reduces the arrangements to test.

Interleaved number series

Some series combine two alternating sequences, such as odd positions following one rule and even positions another. Check alternate terms before assuming a single pattern.

Letter position coding

Convert letters to numbers 1 to 26, then test a constant shift first. If that fails, try reverse alphabet, position sums or alternating shifts.

Data sufficiency method

Test each statement alone first, then only combine if neither suffices. Stop as soon as sufficiency is established; the actual value is not required.

Weakening an argument

To weaken a claim, supply evidence that the stated cause is absent, an alternative cause exists, or the sample supporting the conclusion is unrepresentative.

Ratio scaling rule

A ratio a : b represents multiples of a common unit. To find actual amounts, divide the given total by the sum of the ratio parts, then multiply each part.