Error Spotting – Choose the part (A–D) that contains a grammatical error, or choose No error if the sentence is fully correct. Sentence (parts correspond to options below): A) Reasonable ambition, if supported B) at persistent efforts, C) is likely to yield D) the desired results.
Correct Answer: at persistent efforts,
Introduction / Context:This question checks preposition choice with support. The idiomatic preposition after supported in this sense is by, not at, when indicating the means or agent that provides support.
Given Data / Assumptions:
- Target collocation: supported by
- Current phrase: supported at persistent efforts
- Intended meaning: efforts provide the support
Concept / Approach:In passive-like constructions, by commonly introduces the agent or the means. Therefore, supported by persistent efforts is the correct phrasing. Using at mis-specifies the relationship and sounds non-idiomatic.
Step-by-Step Solution:
Step 1: Identify the head verb supported and its expected preposition.Step 2: Replace the incorrect preposition at with by.Step 3: Confirm that the noun phrase persistent efforts naturally follows by.Corrected fragment: supported by persistent efforts,Verification / Alternative check:Parallel examples: sustained by hard work; powered by solar energy. The by-phrase introduces the source or agent of support.
Why Other Options Are Wrong:
- A) Conditional modifier is grammatical.
- C) Predicate is acceptable and agrees with the singular subject ambition.
- D) Object noun phrase the desired results is idiomatic.
Common Pitfalls:Prepositions are often confused due to first-language influence. Memorize core collocations such as dependent on, interested in, and supported by.
Final Answer:Option B contains the error. Use by instead of at.