In this English grammar error spotting question on tense and agreement, identify the incorrect part of the sentence: "Emperor Ashoka have conquered Kalinga before he embraced Buddhism."

Introduction / Context:
This question examines both subject verb agreement and the correct use of past perfect tense in English. The sentence is "Emperor Ashoka have conquered Kalinga before he embraced Buddhism." The learner must identify whether the verb phrase properly matches the subject and whether the sequence of past actions is correctly expressed. This is particularly important in historical contexts, where one past action clearly precedes another.

Given Data / Assumptions:

• The sentence refers to two past events: the conquest of Kalinga and the adoption of Buddhism by Emperor Ashoka.
• Segment (a) is "Emperor Ashoka".
• Segment (b) is "have conquered Kalinga".
• Segment (c) is "before he embraced Buddhism.".
• Segment (d) is "No error".
• We assume that the conquest occurred earlier than his embracing Buddhism.

Concept / Approach:
First, the subject "Emperor Ashoka" is singular and requires a singular verb. Therefore, "have conquered" should be "has conquered" if present perfect were used. Second, the sentence describes one action happening before another past action, which is a classic situation for using past perfect for the earlier action and simple past for the later action. The best form is "had conquered Kalinga before he embraced Buddhism." This shows clearly that the conquest preceded his change of faith. Hence, segment (b) is incorrect in its current form.

Step-by-Step Solution:
Step 1: Identify the subject "Emperor Ashoka", a single historical figure. Step 2: Note that the verb phrase "have conquered Kalinga" uses the auxiliary "have", which usually goes with plural subjects. Step 3: Recognise that for a singular subject, the present perfect would be "has conquered", but the presence of "before he embraced Buddhism" suggests a sequence of two past actions. Step 4: Apply the rule that when one action happens before another in the past, we normally use past perfect for the earlier action: "had conquered Kalinga". Step 5: Leave segment (c) "before he embraced Buddhism." in the simple past, as it correctly describes the later action. Step 6: Conclude that segment (b) is incorrect and should be changed to "had conquered Kalinga".

Verification / Alternative check:
Rewrite the corrected sentence: "Emperor Ashoka had conquered Kalinga before he embraced Buddhism." This version clearly shows that the conquest was completed prior to his turning towards Buddhism. Compare with other examples such as "She had finished her homework before she went out to play" or "They had left the city before the storm began." In each case, past perfect marks the earlier of two past actions. This comparison confirms that the original verb phrase "have conquered Kalinga" is not appropriate.

Why Other Options Are Wrong:
Option (a) "Emperor Ashoka" is a correct proper noun phrase referring to a historical ruler. Option (c) "before he embraced Buddhism." correctly describes the later action in simple past tense. Option (d) "No error" cannot be chosen because the verb form in segment (b) is plainly incorrect.

Common Pitfalls:
Students sometimes ignore the effect of time markers like "before", "after", or "when" on tense choice. They also confuse "has" and "have" with singular and plural subjects. A good method is always to identify the sequence of events and then decide whether simple past is enough or whether past perfect is needed to show the earlier action clearly. Practising with timelines and several example sentences makes this concept much easier to apply in exams.

Final Answer:
The incorrect part is option (b) "have conquered Kalinga". It should be "had conquered Kalinga". Therefore, the correct answer is "have conquered Kalinga".