How French works
A clause is a group of words containing at least a subject and a verb. The subject is the element of a clause about which an action or state is presented, and the verb is the element expressing this action or state.
Where a clause forms a sentence on its own, this is called an independent clause. For example:
Sara will visit her mother tomorrow
subject = Sara verb = will visit
Very often a clause contains one or more clauses within it. In this case the "containing" clause is called a main clause, and the clause being contained within the main clause is called a subordinate clause. For example:
Sara will visit her mother before she goes home
main clause = she will visit you + subordinate clause
subordinate clause = before she goes home
A main clause must contain a subject, a conjugated verb (one like will visit that changes its form according to its role in the sentence) and a subordinate clause. A subordinate clause contains a subject and any form of verb, conjugated or unconjugated (like to visit or visiting that never changes its form).
The most common types of clause in French are:
Il a dit qu’il serait en retard
He said that he would be late
Il viendra te voir avant que tu ne partes
He'll come and see you before you leave
Il m'a demandé si j'avais été en retard
He asked me if I had been late
Il y a une femme qui veut te voir
There's a woman who wants to see you
Clauses are important because they express the individual ideas that form the building blocks of what we say or write. For greater efficiency and clarity we insert subordinate clauses into other main clauses. In this way our language is not a series of simple ideas strung along by connecting words like and and then (this is very much how young children use language) but a progressive development of interconnected ideas more accurately reflecting the complexity and subtlety of our thought processes.
Furthermore clauses enable us to express ideas with much more precision.
In the above independent clause we read that Sara will visit her mother
Knowledge of clauses is particularly important in French because elements of a clause change according to what type of clause they are in. Take, for example, the following sentence containing a que clause:
Je veux que tu sois de retour avant minuit
I want you to be back by midnight
main clause = Je veux + subordinate clause
subordinate clause = que tu sois de retour avant minuit
Here, the fact that a verb expressing the idea of "wishing" is followed by a que clause means that the verb in the subordinate clause must be in the subjunctive .
We have seen in section 1.1 above that the subject is the element of a clause about which an action or state is presented. Another important element of the clause is the object, which can be direct or indirect. A direct object is one which experiences the direct action of a verb:
I gave the money to my mother
the money = direct object of gave
An indirect object is one acting as the beneficiary of the action of a verb and its direct object.
I gave the money to my mother
my mother = indirect object of gave
Subjects and object are essential to understanding what is happening in a sentence. For example, in the sentence The dog bit the postman, the fact that we know that the dog is the subject and the postman the object tells us that it is the dog that bit the postman, and not the other way round!
These terms are particularly important when it comes to learning French because French has so many words which take different forms according to whether they are subject, direct object or indirect object. Take, for example, the following sentences:
Le chien qui a mordu le facteur était furieux
The dog that bit the postman was angry
Le facteur qu’a mordu le chien était furieux
The postman who(m) the dog bit was angry
Here, it is only through knowing that qui replaces a subject and que or qu’ replaces an object that we can tell that in both cases it is the dog doing the biting!