Nouns and their relatives IV: relative clauses

• The book calls these, with unnecessary ponderousness, "adjectival clauses with the indicative". They're an example of a subordinating construction, a way of stringing more than one clause together into a sentence. Let's look quickly at that idea in general terms before we go on to look at relative clauses in particular.

• A clause is any group of words centred on a verb: the cat sat on the mat, the man bit the dog.

• You can have more than one clause in a sentence: the man bit the dog and the cat sat on the mat. In this instance, you've got two clauses each of which could have been a self-contained sentence on its own, and they're linked together with the simple conjunction and. (Remember a conjunction is a little word that bolts parts of sentences together.) You could do something similar with or, but, and so forth.

• But there are ways of stringing clauses together that are less egalitarian: the cat sat on the mat because the dog was biting the man. Here the first clause, which could stand as a complete sentence on its own, is what we call the main clause, and the second clause, which is incomplete in itself, is what we call a subordinate clause. Note that the order of the clauses doesn't tell you anything about which is main and which is subordinate; in English, and even more so in Latin, you can stick a subordinate clause before, after, or even inside a main clause:
  

• This process of spotting the boundaries between clauses is an important technique in Latin translation, where sentences are often quite long and have several subordinate clauses hanging off a single main clause and sometimes off each other.

• Most subordinating constructions in Latin work exactly the same as their English equivalents, and it's as usual just a matter of realising what you do in your own language and then recognising the same thing in another. There are subordinating constructions of causality (because, since), time (before, after, while, etc.), and place (where, etc.).
  

• But the reason all this is in a section on agreement is that there's one very common and important kind of subordinating construction that doesn't use conjunctions at all; instead, it uses the relative pronoun qui, quae, quod. Suppose the one who sat on the mat was the man instead of the cat. You could say it crudely like this:
  

• But a much more natural way would be to avoid the repetition by using a relative pronoun:
  

• What a relative pronoun does, in Latin as in English, is to serve as a placeholder in a subordinate clause for something in the main clause outside it. Because it's a pronoun, it has to have the right ending in terms of the three noun-family elements of case, number, and gender. But because it's referring to something outside as well as inside its own clause, it has to borrow its number and gender from that something outside - what's technically called its antecedent. Here it's who rather than which because it's a person rather than a thing. The case still comes from its own clause, because case is all about how words relate to their own verbs. Here the pronoun is the object of the verb bit, so it's the accusative whom rather than the nominative who, despite the fact that the man is the subject of his own verb bit. Like most constructions, this works exactly the same in Latin as in English, so you've been doing this all your life.
  

• So the rule is that a relative pronoun agrees in number and gender with its antecedent, but takes its case from its own clause.