Most children go through a phase where every second sentence seems to start with why? For example:
Why is it raining?
Why did Sally hit me?
Why does Sally always get a star from the teacher?
Why did Fluffy have to die?
Because the clouds are crying.
Because you pulled her hair.
Because she works hard.
Because Fluffy is a rabbit, and rabbits don't live very long.
What neither the child nor his long-suffering parent are aware of is that in these examples, the whys ask different questions and the becauses give different kinds of answers. In some languages, in fact, we would use different words for them: Turkish has three words for why, and until recently even English had two (the other being wherefore, as in "wherefore art thou Romeo?") We would expect, then, that Lojban would have at least four words for why, but in fact it doesn't, since all such questions are handled with ma. What Lojban does have is four words for because.
Going back to the first question, "Why does it rain?", the child is asking for a physical explanation, and this is what he gets. If we express the rather unlikely explanation in Lojban, we get
rinka means 'cause' in a physical or mechanical sense:
lenu lei dilnu cu klaku cu rinka lenu carvi
the-event the-mass-of cloud weep physically-cause the-event rain
The clouds' crying is making it rain.
To change this 'cause' to a 'because', we can use ri'a. This is a sumti tcita derived from rinka, in the same way that we saw de'i derived from detri in Lesson 5. So it adds a new place to the bridi it sits in: just as de'i means 'with date', ri'a means 'with physical cause'. This means we can now say
x1 (event/state) effects/physically causes effect x2 (event/state) under conditions x3
which is much more elegant. (Note that Lojban does not need the empty it in It's raining.)
carvi ri'a lenu lei dilnu cu klaku
The reason I have emphasised that rinka and ri'a only deal with physical causes is that it cannot apply in many cases where an English-speaker would use because. Consider the second example. If we say
this is nonsense, since it means that little Joey pulling Sally's hair physically caused her to hit him, which would only be true if Joey had pulled her hair so hard that she had fallen on top of him, perhaps.
la salis. darxi do ri'a lenu do lacpu lei kerfa
Sally hits you with-physical-cause you pull the-mass-of hair