There is a cluster of Part 5 items built around the idea of "so much of something that a result follows," and they are unusually easy to get wrong because the four candidate structures — so ... that, such ... that, too ... to, enough ... to — all express roughly the same thing. The instructions were ____ complicated that most users gave up could plausibly start with so, such, too, or very, and only one is grammatical. The good news: these items are decided entirely by what word occupies the blank and what surrounds it. You never need to interpret the sentence. You slot-match.
The core split: what follows the blank?
Look immediately to the right of the blank and classify what you see. That classification picks the structure.
- Blank + adjective/adverb alone → so (
so complicated,so quickly). - Blank + (adjective +) noun → such (
such a complicated process). - Blank + adjective +
to-infinitive (with a negative result) → too (too complicated to follow). - Adjective + blank +
to-infinitive (with a positive/sufficient result) → enough (clear enough to follow).
That is the whole engine. so and such both set up a that-clause; too and enough both set up a to-infinitive. Which of the two you pick inside each pair depends on the adjective-versus-noun test for so/such, and on word order for too/enough.
so vs. such — the adjective/noun test
Both mean "to such a degree, with this result." They differ only in what they attach to.
- so attaches to an adjective or adverb by itself:
The demand was so high that we sold out.so+high(adjective, no noun). - such attaches to a noun phrase:
It was such a high demand that we sold out.such+a high demand(noun phrase).
The reliable test: is there a noun after the descriptive word?
so + adjective— no noun:so successfulsuch + (a/an) + adjective + noun:such a successful launch
Watch the article. With a singular countable noun, such takes a/an, and the order is fixed: such + a + adjective + noun, never "a such" and never "such successful a launch." TOEIC builds distractors by scrambling exactly this order.
too vs. enough — same meaning family, opposite word order
Both set up a to-infinitive, but they sit on opposite sides of the adjective and carry opposite polarity.
- too comes before the adjective and signals excess → a negative result:
The box was too heavy to lift.(excess weight → could not lift). - enough comes after the adjective and signals sufficiency → a positive result:
The box was light enough to lift.(sufficient lightness → could lift).
The word-order rule is the trap. enough follows the adjective (clear enough, fast enough), but it precedes a noun (enough time, enough staff). So:
- adjective + enough:
experienced enough to lead - enough + noun:
enough experience to lead
TOEIC will offer enough experienced as a distractor. It is wrong because experienced is an adjective, and after an adjective enough must come second. If you see enough before what is clearly an adjective, eliminate it.
The very decoy
Almost every item in this family plants very as a fourth choice. very intensifies (very complicated) but it cannot set up a result clause — no that-clause, no to-infinitive follows it in this structure. So the fastest first move on any result-clause item is: if the sentence has a that-clause or a to-infinitive expressing a consequence, cross off very immediately. It removes one of four choices for free.
Worked examples
Item 1. The report was ____ detailed that the committee needed a week to review it. Choices: so / such / too / very. There is a that-clause and the blank is followed by detailed (adjective, no noun) → so. such needs a noun; too needs a to-infinitive; very cannot take that.
Item 2. It was ____ a productive meeting that we scheduled another one immediately. Choices: so / such / too / very. that-clause present, and the blank is followed by a productive meeting (noun phrase) → such. so would be correct only if it read "so productive that."
Item 3. The deadline was ____ tight to complete the project properly. Choices: so / such / too / enough. There is a to-infinitive with a negative result (could not complete properly), and tight is an adjective right after the blank → too. enough would have to follow the adjective (tight enough), so it is eliminated by word order alone.
Item 4. The prototype was reliable ____ to move into production. Choices: enough / too / so / such. The blank comes after the adjective reliable and before a to-infinitive with a positive result → enough. Position alone settles it.
The one-line reflex
For every item in this cluster, run two checks in order: (1) is the result introduced by that or by to? — that picks the pair; (2) is there a noun after the blank, or is enough before or after the adjective? — that picks within the pair. You never read for meaning. You read for the structural signals.
This is the same solve-on-structure discipline that governs the rest of Part 5. If you want the neighboring mechanical item types drilled the same way, work through the countable-versus-uncountable quantifier items and the adverb-versus-adjective slotting after linking verbs. For how these individual reflexes fit into a timed reading plan, see our reading strategies by question type guide.
Result-clause items look like comprehension questions and are really pattern-matching questions. Learn the four slots, cross off very on sight, and this whole family becomes automatic points.