SAT CONFUSABLE PAIRS

Precipitate vs Precipitous and 9 Other SAT Word Pairs Students Mix Up

Precipitate is normally a verb meaning to trigger something suddenly; precipitous is an adjective meaning steep, or done in reckless haste. A shortage precipitates a crisis, and the crisis causes a precipitous fall in prices. That single distinction - which word is doing the causing and which is describing the shape of the fall - is the pattern behind most of the ten pairs below, all drawn from BARU Vocab's 3,600-word high-frequency SAT list.

Confusable pairs cost more points than rare words do, because a student who half-knows both members will confidently pick the wrong one. Rare words at least trigger caution. The table gives each pair's meanings, how they diverge, where each sits in the frequency ranking, and a one-line tell you can recall under time pressure.

Word A	Word B	How they differ	Which the SAT tends to test
precipitate to cause an event or situation, typically an undesirable one, to happen suddenly or prematurely; (adj.) hasty and undeliberated	precipitous dangerously high or steep; or done with excessive haste, rash and sudden	Precipitate is normally the verb that triggers something; precipitous is the adjective describing a steep slope or a headlong drop.	precipitate (rank 1,969) appears earlier than precipitous (2,812)
exacerbate to make a bad situation, problem, or condition worse	exasperate to irritate or annoy someone intensely; to infuriate	Exacerbate acts on a situation; exasperate acts on a person's patience.	exacerbate (rank 2,641) is Tier 2; exasperate (3,411) is a Tier 3 discriminator
collaborate to work jointly with others on a shared project or goal	corroborate to confirm or support a statement, theory, or finding by providing additional evidence	Collaborate is about working together; corroborate is about evidence backing up a claim.	collaborate (rank 706) is core vocabulary; corroborate (2,656) shows up in argument-analysis questions
tenuous too weak or slight to hold up; insubstantial or not firmly grounded	tenacious holding firmly to a purpose, position, or belief; persistent and not easily dislodged	They pull in opposite directions: tenuous means barely holding, tenacious means refusing to let go.	tenacious (rank 1,365) is more frequent than tenuous (3,039)
indigenous originating or occurring naturally in a particular place; native to a region	indigent poor; lacking the basic necessities of life	Indigenous is about origin and place; indigent is about poverty.	indigenous (rank 228) is Tier 1 and common in science and history passages; indigent (1,894) is Tier 2
ostensible stated or appearing to be true while concealing a different reality; nominal	ostentatious characterized by conspicuous display intended to impress; showy and pretentious	Ostensible flags a stated reason the author doubts; ostentatious describes visible showing off.	ostentatious (rank 2,941) and ostensible (3,319) are both Tier 3
substantial of considerable size, value, or importance; large or significant	substantive having real importance or substance; concerning essential content rather than form or procedure	Substantial measures quantity; substantive measures whether something touches the real issue.	substantial (rank 243) is Tier 1; substantive (1,993) is Tier 2
hoard to accumulate and store a large supply of something, often secretively; a hidden stock	horde a large, often disorganized or overwhelming crowd of people or creatures	A hoard is a pile of things; a horde is a crowd of beings.	horde (rank 1,182) is Tier 1; hoard (2,543) is Tier 2
inflict to cause something unpleasant or painful to be suffered by someone	afflict to cause persistent pain, suffering, or distress to someone	Someone inflicts harm on a victim; a condition afflicts the person who suffers it.	inflict (rank 2,143) is Tier 2; afflict (3,002) is Tier 3
obtuse slow to understand; lacking sharpness of intellect or perception	abstruse difficult to understand; obscure or esoteric in nature	Obtuse describes a dull reader; abstruse describes a difficult text.	obtuse (rank 2,627) is Tier 2; abstruse (3,398) is Tier 3

One-line tells

precipitate / precipitous — A shortage precipitates a crisis; the crisis causes a precipitous fall in prices.
exacerbate / exasperate — Budget cuts exacerbate a shortage; the third delay exasperates the committee.
collaborate / corroborate — Labs collaborate on research; a second witness corroborates the first.
tenuous / tenacious — A tenuous link snaps under scrutiny; a tenacious investigator will not.
indigenous / indigent — Indigenous plants belong to the valley; indigent patients cannot pay the bill.
ostensible / ostentatious — The ostensible purpose hides the real one; the ostentatious car hides nothing at all.
substantial / substantive — A substantial raise is a big one; a substantive change alters the policy itself.
hoard / horde — Archaeologists find a hoard of coins; a horde of tourists finds the town.
inflict / afflict — A storm inflicts damage on a town; a disorder afflicts a child - the grammar gives it away.
obtuse / abstruse — The person is obtuse, the lecture is abstruse - one is the mind, the other is the material.

Self-check: five questions

Fill the blank, then compare with the answer below each item.

The drought ____ an already serious food shortage.
Answer: exacerbated - the situation got worse. Exasperated would need a person as the object.
Her evidence ____ the earlier account given by the survey team.
Answer: corroborated - it confirmed the claim. Collaborated would need people working together.
Investors panicked at the ____ decline in the currency's value.
Answer: precipitous - the adjective for a steep drop. Precipitate here would be the verb that caused it.
The committee dismissed the revisions as cosmetic rather than ____.
Answer: substantive - the contrast is form versus real content, not size.
The ____ reason for the merger was efficiency, but analysts saw a tax motive.
Answer: ostensible - a stated reason concealing another. Ostentatious would describe showy display.

Why these pairs behave the way they do

Three mechanisms explain almost every mix-up here. The first is part of speech. Inflict and afflict are both verbs, but their objects differ: harm is inflicted on someone, while a condition afflicts someone. Reading the sentence's grammar settles it faster than recalling a definition. The second is near-opposition. Tenuous and tenacious share a Latin root meaning to hold, and then split - one barely holds, the other will not let go. Pairs like that are worth learning together precisely because their shared origin is what makes them dangerous.

The third mechanism is scale versus substance. Substantial and substantive look almost identical and both descend from substantia, yet one measures how big a thing is and the other measures whether it addresses the real issue. Reading & Writing questions built on author attitude lean on that difference: calling a reform "substantial but not substantive" is a criticism, and a student who reads the two words as synonyms will miss the author's point entirely.