Four Sentences Before the Letter Is Printed
A school secretary has drafted a letter to parents about a trip and asks a colleague to check the sentences before printing:
A. 'Students who have not returned their forms by Friday will not be allowed on the trip.' B. 'Students, who have not returned their forms by Friday, will not be allowed on the trip.' C. 'The coach leaves at seven, please arrive by six forty-five.' D. 'There are three things to bring: a packed lunch, a raincoat and a water bottle.' E. 'Its important that every student brings there own medication.'
The colleague is told to change nothing that is already acceptable in British English, because the headteacher dislikes needless corrections.
1. Which of A or B should be printed, and what exactly does the pair of commas in B do to the meaning?
Read the worked answer
Print A.
In A the clause 'who have not returned their forms by Friday' is restrictive: it identifies which students are affected. Read it as an instruction and it makes sense - only the non-returners are barred, everyone else travels.
In B the same clause is non-restrictive. The commas tell the reader that the clause is extra information about all students, not a way of picking some out. The sentence therefore says that the whole group has failed to return forms and the whole group is barred - which is almost certainly untrue, and would be a strange thing to announce. The commas also imply the reader already knows this fact about the group.
The point being tested: punctuation is not decoration. Here a pair of commas changes who is allowed on the coach. Where a clause is doing identifying work, it must not be fenced off by commas.
2. Name the error in C and in E, and state whether D needs correcting.
Read the worked answer
C - comma splice. Two independent clauses ('The coach leaves at seven' / 'please arrive by six forty-five') are joined by a comma alone. Fix with a full stop, a semicolon, or a conjunction: 'The coach leaves at seven; please arrive by six forty-five.' The semicolon is the neatest here because the two statements are closely related.
E - two errors. 'Its' should be 'It's' (contraction of it is, not the possessive its), and 'there' should be 'their' (possessive determiner, not the place word). Corrected: 'It's important that every student brings their own medication.' Note that 'their' with a singular antecedent is standard British usage and should not be corrected further.
D - leave it alone. The clause before the colon is a complete sentence introducing a list, which is exactly what a colon is for, and British English commonly omits the comma before the final 'and'. The list is parallel (article plus noun in each item).
The judgement: the task rewards distinguishing a genuine error from a style preference. Changing D would be the kind of needless correction the headteacher objects to, and it would suggest the checker cannot tell the two apart.