Does a missing comma in a sentence change the meaning of the sentence? Look at this sentence: The panda eats shoots and leaves. Now insert commas after the words ‘eats’ and ‘shoots’ and the meaning of the sentence changes completely. The sentence “The panda eats, shoots, and leaves” may be interpreted by someone as this: A panda ordered a pizza in a restaurant, killed the waiter with a pistol, and left.
What is the difference in meaning between the sentences below?
1. My sister who is in the US is a doctor.
2. My sister, who is in the US, is a doctor.
In the second sentence, the clause “who is in the US” is additional information and therefore, is set off by commas. The first sentence implies that the writer has more than one sister. The comma in a sentence acts as a pause. Read the two sentences. You will read the first sentence without any pause and the second sentence with pauses after “my sister” and after “who is in the US”. Compare these sentences:
1. The movie which we watched yesterday is a very good entertainer.
2. Shashi Tharoor, Minister of State for Human Resource Development, will deliver the closing address in the ThinkEdu Conclave, organised by The New Indian Express.
In the first sentence, the part “which we watched” is not set off from the rest of the sentence. The subject “movie” is restricted. The reference is to the movie that we watched yesterday and not last week or last month or earlier. Since the focus is on a particular movie that was watched yesterday, there is no comma after the word “movie”. In other words, the phrase “which was watched” is essential to the basic meaning of the sentence. So, this part is not separated by commas. In the second sentence, the additional information “Minister of State for Human Resource Development” is not essential to convey the basic meaning. Even without this piece the sentence conveys the meaning.
The learner should know whether there is a restrictive or nonrestrictive element in a sentence in order to know whether the comma is required. A restrictive element is one that is essential to the basic meaning of the sentence whereas a nonrestrictive element is one that is not essential to the basic meaning of the sentence. A restrictive clause limits the possible meaning of a preceding subject whereas a nonrestrictive clause does not restrict the meaning of the subject and tells something about a preceding subject. Look at these examples:
1. The boy who is in sky-blue jeans and black T-shirt is Sheela’s cousin.
2. The woman who has long hair is an IAS officer.
4. The members of the club, who own Benz cars, are affluent.
5. These students, who studied in rural schools, need training in communication skills.
The first two sentences have restricted clauses. In the first sentence, the subject “boy” is restricted, that is, he is wearing sky-blue jeans and a black T-shirt and other boys in the group are not wearing sky-blue jeans and black T-shirts. In the second sentence, the subject “woman” is restricted, ie, she has long hair and the other women in the group do not have long hair. The last two sentences have nonrestrictive clauses and so are set off by commas.
— rayanal@yahoo.co.uk