Questions: Commas with Introductory Dependent Clauses

Question 1

Which sentence is correctly punctuated?

• A. Because it was raining we stayed inside.
• B. Because it was raining, we stayed inside.
• C. Because, it was raining we stayed inside.
• D. We stayed inside, because it was raining.

Answer: (B)

When a dependent clause introduces a sentence, it must be followed by a comma. 'Because it was raining' is the introductory dependent clause; 'we stayed inside' is the independent clause — a comma is required after 'raining.' Option A omits the required comma. Option C places the comma immediately after the conjunction ('Because,') rather than at the end of the full dependent clause — a common misplacement. Option D inserts an unnecessary comma before a trailing dependent clause, which does not require punctuation when it follows the main clause.

Question 2

A writer has the sentence 'The match was postponed because lightning struck the field' and moves the dependent clause to the front. Which version is correctly punctuated?

• A. 'Because lightning struck the field the match was postponed.' — no comma needed since the meaning is clear
• B. 'Because lightning struck the field, the match was postponed.' — comma required after the introductory dependent clause
• C. 'Because, lightning struck the field, the match was postponed.' — commas surround the opening clause
• D. 'Because lightning struck the field: the match was postponed.' — a colon separates the setup from the result

Answer: (B)

When the dependent clause moves to the front of the sentence, a comma is required after it. In the original version ('The match was postponed because lightning struck the field'), no comma is needed because the dependent clause follows the independent clause. Reordering changes the punctuation requirement. The comma marks the syntactic boundary between the introductory clause and the main clause — it is not optional even when the meaning is unambiguous.

Question 3

A comma should be placed immediately after the subordinating conjunction that opens a dependent clause — for example: 'Although, the weather was cold, the children played outside.'

• T. True
• F. False

Answer: False

The comma comes at the end of the entire dependent clause, not immediately after the subordinating conjunction. 'Although, the weather was cold, the children played outside' is incorrect. The correct version is 'Although the weather was cold, the children played outside' — the comma follows 'cold' (the end of the dependent clause), not 'although' (the opening conjunction). Placing the comma right after the conjunction interrupts the clause before it is complete.

Question 4

When a dependent clause follows the main clause rather than introducing it, no comma is needed.

• T. True
• F. False

Answer: True

The rule is entirely position-dependent. 'We started the meeting when she arrived' — dependent clause trails the main clause, no comma needed. 'When she arrived, we started the meeting' — dependent clause introduces the sentence, comma required. The meaning is identical; only the order (and therefore the punctuation) differs. A useful editing test: flip the sentence so the independent clause leads — the flipped version needs no comma, confirming that the original introductory version requires one.

Question 5

Why does the position of a dependent clause — before or after the main clause — determine whether a comma is required?

Model answer: When the dependent clause comes first, readers encounter an incomplete thought before the main point arrives. The comma signals 'the introductory part is finished; here comes the main clause,' managing the reader's processing load and marking the structural boundary. When the dependent clause follows the main clause, the reader already has the main idea and the dependent clause elaborates it — no structural signal is needed, so no comma is required.

The comma is doing structural work, not stylistic work. This is clearest in cases where omitting it causes momentary misreading: 'When the dogs attack children are frightened' briefly reads 'attack children' as a verb-object unit. The comma ('When the dogs attack, children are frightened') prevents that misreading. The rule exists because of real comprehension risks created by the introductory-clause word order — not as arbitrary convention.