In the following sentence, identify the part that contains an error, or select "No error": "Soon as he / saw the policeman, / he ran away."

Introduction / Context:
This question is an example of error spotting in English grammar. The sentence describes a simple past situation in which someone sees a policeman and immediately runs away. The task is to examine each underlined segment and decide which part contains a grammatical or structural error, or decide that the sentence is correct as it is.

Given Data / Assumptions:

- The sentence is broken into four labelled parts: A, B, C, and D. - Part A: Soon as he - Part B: saw the policeman, - Part C: he ran away. - Part D: No error, which is chosen only if A, B, and C are completely correct.

Concept / Approach:
The phrase that expresses immediate sequence of events in standard English is as soon as, not soon as on its own. The complete structure should be as soon as he saw the policeman. Parts B and C appear grammatically correct in tense and word order. Therefore, the focus falls on Part A, which is missing the word as at the beginning, and this omission makes the expression incomplete and incorrect.

Step-by-Step Solution:
Step 1: Read the entire sentence mentally as it is written: Soon as he saw the policeman, he ran away. Step 2: Recall the standard conjunction used to show one action happening immediately after another, which is as soon as. Step 3: Compare the standard structure with Part A. The given part Soon as he lacks the initial as and therefore does not match the correct phrase. Step 4: Check Part B, saw the policeman, and confirm that it is a correct simple past clause. Step 5: Check Part C, he ran away, and see that it is a correct independent clause in the simple past. Step 6: Since only Part A is faulty, mark option A as the part containing the error.

Verification / Alternative check:
A good way to verify the answer is to rewrite the sentence correctly and see where the change occurs. The corrected version is: As soon as he saw the policeman, he ran away. The only difference from the original is that an extra as has been added before soon. Parts B and C remain unchanged, which confirms that the original error lies in Part A alone.

Why Other Options Are Wrong:
Part B uses saw, which is the correct simple past form of see, followed by the object the policeman. There is no error in tense or article usage. Part C, he ran away, is also correct and expresses a completed action in the past. Therefore, choosing B or C would incorrectly mark a correct phrase as wrong. Part D, No error, would imply that the entire sentence is acceptable, but the missing as shows that this is not true.

Common Pitfalls:
Many learners get used to spoken shortcuts and may hear expressions like Soon as he came spoken quickly. However, in formal written English, the full form as soon as is required. Another common mistake is to suspect an error in verb tense when the real issue is a missing word in a conjunction. The safest strategy is to check fixed phrase patterns such as as soon as, in spite of, or as far as before looking at tenses.

Final Answer:
A is the correct choice, because Part A is missing the word as and should be written as As soon as he.