A clause makes up a part, or several parts of a sentence. A clause can also be a sentence in itself. They way we structure our clauses can provide real power over the control of our sentences. Firstly, we should take a look at different clause types.
The main clause will contain a subject and a verb. It will make sense on its own and is grammatically identical to a simple sentence. It’s different from a simple sentence in that a main clause can also be part of a longer sentence with more than one clause. In this instance, the main clause won’t require a full stop if it’s placed at the start of the sentence, but if it’s placed at the end of the sentence, it won’t require a full stop.
He was happy with the deal.
He was happy with the deal, because it works out in his favour.
Because it worked out in his favour, he was happy with the deal.
Just as a main clauses makes sense on its own, a subordinate clause will not make sense on its own. It will typically start with a subordinating conjunction, such as although, after, before, because, how, if, once, since, until. By placing a subordinating conjunction before a main clause, we can often turn it into a subordinate clause.
Because he was happy with the deal…the previous example of a main clause no longer makes sense on its own once we’ve placed a subordinating conjunction.
A relative clause is a type of subordinate clause, that will contain a relative pronoun to refer back to a noun or phrase.
The school banned mobile phones that can access the internet.
The main clause is in bold, ‘that’ is the relative pronoun indicating that the subordinate clause is relative to the noun ‘mobile phones’.
Again, embedded clauses are a type of subordinate clause. They are embedded within another clause and generally marked by commas. Embedded clauses can be removed from the sentence and the sentence left behind will still make sense.
The cheese, from the local shop, was mouldy.
We can see that the embedded clause can be inserted or removed from the main clause and the main clause remains grammatically correct in both cases.
Variations in Terminology
Main clauses and subordinate clauses can be referred to as Independent and dependant clauses respectively. The English curriculum uses main clause and subordinate clause.