What are Kausalsätze?

 
Kausalsätze are known in English as causal clauses. In a sentence, these clauses will inform the listener or reader about the reason(s) for something. In English, we usually use conjunctions like "because", "as" to introduce causal clauses. Kausalsätze are very important for human communication and cognition as our brains will always naturally seek to explain objects, events and phenomena which we observe or perceive. It is simply ingrained in our minds to want to know 'why'. In German as in English, there are many different ways to state the reason(s). In the following, we will introduce three different ways -- using weil, denn and deshalb/deswegen.

Kausalsätze with weil

 
Of all the possible connectors for Kausalsätze, weil is probably the most commonly used. It is a Subjunktion (or subordinierende Konjunktion) and introduces a Nebensatz or, in English, a subordinating clause. Take a look at the following examples and determine the verb position after weil:

Morgen kann ich länger schlafen, weil es ein Feiertag ist.
In diesem Winter muss Mieter mehr Nebenkosten zahlen, weil das Heizöl mehr kostet.

The word weil and the verbs are marked in blue above. Now, can you formulate the rule for positioning the verb after weil? 

* Special Note: In spoken situations, the verb is sometimes placed in the second position after weil. This is colloquial. In such a case, there is usually a slight pause after weil before the speaker names the reason and completes the sentence, e.g.

* Ich habe jetzt wirklich keine Lust auf eine Party, weil  ...  ich habe morgen einen Test.

Kausalsätze with denn

  
Unlike weil, denn is a koordinierende Konjunktion. In linguistics, it may be simply called a Konjunktion. The verb will now be in a different position. Consider the following examples and determine both the verb position and the position of denn:

Paul kennt die Schmidts sehr gut, denn er wohnte früher im selben Dorf wie sie.
Ich kann das Chaos nicht verstehen, denn gestern war alles doch noch in Ordnung. 

The conjunction denn and the verbs are marked in blue above. Now, can you formulate the rule for positioning the verb after denn?  

Kausalsätze with deswegen/deshalb

  
Sentences starting with deshalb or deswegen are, strictly speaking, not Kausalsätze. That's because the reason(s) are actually stated in the sentence preceding deshalb/deswegen. Both deshalb and deswegen are actually adverbs and mean "therefore", "thus" or "that's why". Consider the following examples and determine both the verb position after deshalb/deswegen:

Herr Karlsson hat sehr viel Wein getrunken. Deshalb darf er jetzt nicht Auto fahren.
Das Haus fanden wir zu teuer; deshalb haben wir es nicht gekauft. 

The adverbs deshalb and deswegen and the verbs are marked in blue above. What is the rule for the verb position? How is it differenr from denn?  

* Special Note: Deshalb and deswegen are preceded by a fullstop (.) or a semi-colon (;). They effectively will start a new sentence.