In the first part of the series on “Understanding the conventions of academic writing”, I discussed these two common error patterns: i) Missing comma after introductory element, and ii) Vague pronoun reference. The focus of the second part is on “using comma in compound sentences”.
A compound sentence has two or more simple sentences. Each simple sentence in a compound sentence expresses a complete thought. Two or more simple sentences can be joined by a semicolon, a colon, or a comma and a joining word. Here are examples:
Semicolon
John watched a movie; Mary played the guitar.
John referred to a book; however, Mary downloaded relevant articles from the Internet to write the assignment.
Colon:
Two simple sentences can be joined by using the colon if the second simple sentence explains or expands the first simple sentence as in these examples:
My trip to Goa was pleasant: we spent considerable time in all the beaches.
We decided to buy the house: it is very important to own a house.
Comma and one of the joining words (for, and, nor, but, or, yet, and so)
John went to Bangalore, but his sister Mary went to Goa.
We’ll meet at the café at 6 pm, or we’ll cancel the programme.
The purpose of using a compound sentence is to tell the reader that the two ideas in the sentence are connected and are equally important and also to inform the reader about the relationship between the two ideas.
When sentences are joined by and, but, for, nor, or, so, yet, it is important to insert a comma before the coordinating conjunction to indicate a pause between two thoughts and to resolve ambiguity. It is a common error to insert a comma after the coordinating conjunction.
Incorrect: We reached the railway station in time but, we couldn’t meet him.
Correct: We reached the railway station in time, but we couldn’t meet him.
Incorrect: Does he want to go to the US for higher studies or, will he study in India?
Correct: Does he want to go to the US for higher studies, or will he study in India?
In very short sentences, the comma is optional if the sentence can be easily understood without it. For example,
She is rich but she doesn’t help anyone
Look at these quotes:
“You can put wings on a pig, but you don’t make it an eagle.” (Bill Clinton)
“The tyrant has fallen, and Iraq is free.” (George W Bush)
In the examples above, coordinating conjunctions are used to connect independent clauses. The insertion of the comma after the first independent clause serves as a pause and helps the reader understand the meaning and relationship between independent clauses better.
Though the trend is to avoid using the comma wherever possible, it is good to know that the insertion of the comma appropriately in compound sentences helps clarify the grammar of a sentence and to resolve ambiguity.
— rayanal@yahoo.co.uk
Errata: The headline for last week’s column should have been “Common English errors that have to be rectified” instead of “has to”. The error is regretted