When two commas are mandatory

Of the following three sentences, only one is correctly punctuated. Can you identify it?

    They will, next week hold the family meeting.

    They will, next week, hold the family meeting.

    They will next week, hold the family meeting.

The second sentence is the one correctly punctuated. The first and third have a grammatical issue because a comma is missing in each of them. In a clause/sentence with an independent clause inserted in it, two commas are required. The inserted piece provides additional information (shedding light on the message in the main clause) but can be removed without injuring the main clause. Now, the commas not only show that the added element is not an integral part of the clause, but they also tell the reader the need for voice variation at that point when reading the clause.

Consider the following sentences too:

He, last year, bought two cars.

They, as a matter of fact, visited the woman in the hospital.

I will, other things being equal, send my contribution this evening.

In each of the clauses, the two commas are mandatory. To avoid either or both, you often have to change the structure:

    He bought two cars last year.

  As a matter of fact, they visited the woman in the hospital.

    Other things being equal, I will send my contribution in the evening.

    I will send my contribution in the evening – other things being equal.

The last example suggests another dimension to the options available. In many cases you have to use the two commas, dashes or brackets can work:

He – last year – bought two cars.

I will – other things being equal – send my contribution in the evening.

He (last year) bought two cars.

I will (other things being equal) send my contribution in the evening.

Uses of the twin commas

To show time:

He, on Sunday, travelled to London.

    President Bola Tinubu, last week, chaired FEC meeting.

To mark out connectors:

    They, therefore, promised to clean the market.

    The three women, however, arrived very early.

To modify a noun as in establishing someone’s title or designation:

This is what applies to nouns in apposition – the appositives. An appositive is a noun that renames a nearby counterpart:

    The FCT Minister, Nyesom Wike, is a controversial politician.

    Atiku Abubakar, a former Vice President, still wants to be President.

In the sentences, ‘Nyesom Wike’ and ‘a former Vice President’ are appositives.

To set apart clauses not essential to the main structure.

Such a nonessential clause is called nonrestrictive:

    The visitor, who arrived after the programme had ended, has apologised to the host.

In the sentence, ‘who arrived after the programme had ended, is nonrestrictive and should be marked with the two commas. When the expression is, however, essential or restrictive, no comma is required:

    The gateman who killed the bird has been sacked.