English grammar error-spotting (dangling modifier with ‘‘While …’’ participial clause): Identify the erroneous part; ensure the introductory modifier has the correct grammatical subject immediately after it: ‘‘While walking slowly in the park / on a quiet summer afternoon / a mad dog suddenly attacked him from behind / No error.’’

Given data

• A: ‘‘While walking slowly in the park’’
• B: ‘‘on a quiet summer afternoon’’
• C: ‘‘a mad dog suddenly attacked him from behind’’
• D: ‘‘No error.’’

Concept / Approach
An introductory participial clause must modify the grammatical subject that immediately follows. Here, the modifier ‘‘While walking …’’ mistakenly attaches to ‘‘a mad dog’’ (illogical). This is a classic dangling modifier.

Step-by-Step evaluation
Part A dangles because the subject that follows in Part C is ‘‘a mad dog’’.

Correction
‘‘While he was walking slowly in the park on a quiet summer afternoon, a mad dog suddenly attacked him from behind.’’ (Now the subject ‘‘he’’ correctly matches the modifier.)

Common pitfalls

• Beginning with a participial clause without immediately placing the intended subject next.

Final Answer
While walking slowly in the park