Why do only some conjunctions push the verb to the end?

Question

In the following examples, the conjunction pushes the verb to the end of the sentence:

Du trinkst, weil du Durst hast.

Ich mag es, wenn es einfach ist.

Der Käse ist gut, obwohl er alt ist.

However, the following sentences don't push the verb to the end of the phrase/sentence:

Ich mag keine Orangen, aber ich mag Äpfel.

Die Frauen trinken das Wasser nicht, denn es ist schmutzig.

Is there a reason why the verb isn't pushed to the end of the sentence?

The conjunctions I have seen that don't follow this rule are the following:

• und
• denn
• aber
• doch

Answer 1

German knows about Hauptsätze (main clauses) and Nebensätze (subordinate clauses).

Hauptsatz

A typical German Hauptsatz, has the verb always in 2nd position (note that this doesn't mean the verb is always the second verb in the sentence).

Ich gehe zur Schule
Anna und ich gehen zur Schule

Exceptions are yes/no-questions

Geht ihr zur Schule?

and imperatives

Geht zur Schule!

where the verb is in first position.

Nebensatz

A Nebensatz has the verb always in last position.

[...], weil er morgen in die Schule geht. [...], obwohl er gestern nicht in der Schule gewesen ist.

Now, some conjunctions combine 2 Hauptsätze (such as und, oder, aber, ...), and other combine a Haupt- and a Nebensatz (such as weil, obwohl, bevor, ...).

The word order is thus not necessarily dependend on the conjuction but on the type of clause you have. This quickly becomes a Chicken-or-the-egg-problem, so remember it the way that works best for you [e.g. this is an X-clause, so ordering is Y, or this conjunction is used with an X-clause, so ordering is Y].

As a rule of thumb: If the sentence can be written by itself, it's a main clause and thus, the Hauptsatz structure must be employed. If the sentence can not stand by itself, it's a subordinate clause and you must use the Nebensatz word order.

Answer 2

You found most of the coordinating conjunctions where the verb order is not changed

und, aber oder, sondern, denn

I wouldn't exactly include doch though.

For the subordinating conjunctions, here is a list of them where the word order is changed

bevor, nachdem, ehe, seit, seitdem, während, als, wenn, wann, bis, obwohl, als ob, sooft, sobald, solange, da, indem, weil, ob, falls, wenn, um … zu, dass, sodass, damit

Schaum's Outline for German is an awesome reference. It is not very expensive and it is very organized.

Best of luck - keep at it.