Choose the sentence that uses efficient at correctly.

Choose the sentence that uses efficient at correctly.

• A. She is efficient at solving complex problems.
• B. She is efficient in solving complex problems.
• C. She is efficient for solving complex problems.
• D. She is efficient with solving complex problems.

Answer: (A)

The main idea is how to pair the adjective efficient with a preposition to describe someone's ability to perform a task. When you’re talking about how well someone can do a specific activity, the natural pairing is efficient at followed by the gerund or the activity. So “efficient at solving complex problems” fits because it clearly says she can solve problems efficiently. Using a different preposition changes the meaning or sounds off. “Efficient in solving complex problems” sounds less natural for describing a person’s skill at a task; it can imply efficiency within a broader domain rather than at the particular activity. “Efficient for solving…” isn’t idiomatic, and “efficient with solving…” would usually refer to using a tool or method rather than the person’s ability to perform the task. If you wanted to emphasize how she performs the task, you could also say “She solves complex problems efficiently,” which uses an adverb, but that’s a different construction.

The main idea is how to pair the adjective efficient with a preposition to describe someone's ability to perform a task. When you’re talking about how well someone can do a specific activity, the natural pairing is efficient at followed by the gerund or the activity. So “efficient at solving complex problems” fits because it clearly says she can solve problems efficiently.

Using a different preposition changes the meaning or sounds off. “Efficient in solving complex problems” sounds less natural for describing a person’s skill at a task; it can imply efficiency within a broader domain rather than at the particular activity. “Efficient for solving…” isn’t idiomatic, and “efficient with solving…” would usually refer to using a tool or method rather than the person’s ability to perform the task. If you wanted to emphasize how she performs the task, you could also say “She solves complex problems efficiently,” which uses an adverb, but that’s a different construction.