Learn English – Can “then” be used as a coordinating conjunction

conjunctionscoordinationsyntactic-analysis

Can the word "then" be used as a coordinating conjunction?

I am confused, because the word seems as if it works as a coordinating conjunction, but I did not see it is classified so. The Cambridge Dictionary Online grammar source classifies it as an adverb and puts it into groups in terms of meaning.

For example, in the following sentence it means "next" according to the website.

He opened the door, then the lights came on and everybody shouted,
‘Happy Birthday’.

Yes, it means "next" in the sentence, but it also connects independent clauses. Because without the word then, the sentence comprises of three simple sentences and I am not sure if it would be grammatically correct as the following. I think in this case the sentence would be run-on (comma splice).

He opened the door, the lights came on and everybody shouted, ‘Happy
Birthday’.

Beside that, if we do not focus on what function the word then has in the sentence, how we can classify that sentence? Is it a simple, compound, or complex sentence? Or neither of them?

It is not simple nor complex. Because it does not have a dependent clause, but a University of Cambridge Grammar book also says a compound sentence must consist of two independent clauses. If there are more than two independent clauses then rewrite them as two sentences. But there are three independent clauses in the example sentence, so how does it work?

In the following example the word then means "in that case" and places in a complex sentence.

If we buy Jason a present, then we’ll have to buy one for Isaac too.

I wonder if I can omit then, but keeping the meaning of the original sentence and would that be grammatically correct?

Best Answer

One of the best tests of a coordinating conjunction is its non-reversible order. We frequently place subordinate clauses beginning with the subordinating conjunction before the main clause, such as:

Because the man overate, he developed a stomach ache.

Coordinating conjunctions cannot be reversed in this way; HOWEVER (!!!)

The word "then" is often used alone, when in reality, in proper usage, it is "AND then". AND is the coordinating conjunction with THEN remaining and adverb of time, indicating WHEN the action occurred.

So, (an incorrectly placed coordinating conjunction... sorry), examining your original sentence:

He opened the door, then the lights came on and everybody shouted, ‘Happy Birthday’.

If we say,

He opened the door, AND then the lights came on, and everybody shouted.

We see that there are actually TWO independent clauses with AND as the coordinating conjunction, with THEN used properly as an adverb.

Hope this clears it up. Just because we don't say (or write) the AND, it is still (grammatically) there, the same way YOU is still the subject in imperatives, even though it is always omitted.

Related Topic