Punctuation That Changes the Verdict: The Restrictive Clause
A sentence-correction item presents: 'The students, who had not revised, failed the test.' The candidate must decide whether the commas are correct and, if the intended meaning is that only the non-revising students failed, rewrite the sentence. A second item reads: 'My brother, who lives in Dhaka, is a doctor' and asks whether the commas should stay. The candidate's rule of thumb is 'commas go around extra information'. In the first sentence, the intended meaning is restrictive: the commas wrongly imply that all the students failed.
1. Apply the restrictive/non-restrictive distinction to both sentences and state the corrected forms with reasoning.
Read the worked answer
Sentence 1: If the intended meaning is that only the students who had not revised failed, the clause is restrictive (it identifies which students), so no commas: 'The students who had not revised failed the test.' With commas, the clause is non-restrictive and presupposes that all the students failed while adding that they had not revised - a different and probably unintended claim. Sentence 2: 'My brother, who lives in Dhaka, is a doctor' - the commas are correct if the speaker has only one brother, because the clause then adds non-essential information. If the speaker has several brothers and the clause identifies which one, the commas must go: 'My brother who lives in Dhaka is a doctor.' The candidate's rule of thumb is half right: commas do mark extra information, but the test is whether removing the clause changes which entity is being referred to. If it does, the clause is restrictive and takes no commas.
2. The candidate asks: 'But the sentence sounds the same when read aloud.' Explain why sound is an unreliable guide here and what test to use instead.
Read the worked answer
Read-aloud intonation is unreliable because a speaker can pause for breath or emphasis at almost any boundary, and written punctuation encodes grammatical and referential structure, not breath. The reliable test is the deletion test: remove the clause and ask whether the remaining sentence still refers to the same set of people. 'The students failed the test' after deleting 'who had not revised' now refers to all students, so the clause was doing identifying work and must be restrictive. 'My brother is a doctor' after deleting 'who lives in Dhaka' still refers to the same person if there is only one brother, so the clause was non-restrictive. A second test is the which/that check in restrictive clauses, though style guides differ on its strictness, so the deletion test should be primary. The exam rewards the structural test, not the ear.