In this error spotting question, read the sentence and identify the part that contains a grammatical or usage error. The sentence is: "In such delicate matters, we often take his advice as he has been effectively handling such cases for a decade."

Introduction / Context:
This question checks your ability to recognise a sentence that is already grammatically correct and to resist the temptation to change what does not need correction. The sentence describes a situation where, in delicate matters, people rely on someone advice because of his long experience handling such cases. Your task is to decide whether any segment contains an error in tense, structure, or word choice.

Given Data / Assumptions:

• Full sentence: "In such delicate matters, we often take his advice as he has been effectively handling such cases for a decade."
• Segments:
  • A: In such delicate matters
  • B: We often take
  • C: His advice as he has
  • D: Been effectively handling such cases for a decade
• Option E represents "No error".
• The time span is "for a decade", which suggests a continuous activity from the past up to the present.

Concept / Approach:
We examine each segment for subject verb agreement, tense use, and idiomatic usage. The clause "we often take his advice" is standard in English. The reason clause "as he has been effectively handling such cases for a decade" uses present perfect continuous, which is appropriate for an activity that started in the past and continues up to the present. There is no mismatch in tense, no incorrect preposition, and no missing articles. Therefore, there is no error in any part of the sentence, and the correct answer is the "No error" option.

Step-by-Step Solution:
Step 1: Check segment A: "In such delicate matters" correctly uses the preposition "in" with "matters" and the adjective "delicate". Step 2: Check segment B: "we often take" correctly uses the adverb "often" with the simple present verb "take" to describe a repeated action. Step 3: Check segment C: "his advice as he has" introduces a reason clause and uses the correct verb "has" to lead into the perfect continuous. Step 4: Check segment D: "been effectively handling such cases for a decade" completes the present perfect continuous construction "has been handling" and includes "for a decade" to show duration, which matches the tense. Step 5: Since no segment contains an error, choose the "No error" option.

Verification / Alternative check:
Try to rewrite the sentence in simpler words to see if the structure is still correct: "In matters that are this delicate, we often take his advice because he has been handling such cases effectively for ten years." The meaning remains the same and confirms that the original grammar is sound. Any attempt to change the tense, for example to "he is effectively handling" or "he handled", would actually weaken the correct idea of long ongoing experience.

Why Other Options Are Wrong:
Choosing A would suggest that "In such delicate matters" is incorrect, but this is a normal expression in English.

Choosing B would indicate a problem with "we often take", when in fact this is a standard way to talk about habitual actions.

Choosing C or D would claim that the perfect continuous clause is wrong, but "has been effectively handling" for a period is precisely the correct pattern.

Common Pitfalls:
Many test takers feel that an error spotting question must always contain an error, so they select a part that seems slightly awkward even when the sentence is correct. Remember that exam instructions explicitly allow for a fully correct sentence. When you find no clear mistake in any segment, confidently select "No error" instead of forcing a change where it is not needed.

Final Answer:
The sentence is grammatically correct as it stands, so the correct choice is "No error".