tan

tan as a preposition

mi moku tan ni: mi wile moku.

I eat because I'm hungry.

tan as a noun

mi sona ala e tan.

I don't know the reason. / I don't know why.

When used as a noun, tan means cause or reason. Of course, that can be helpful when you want to translate a sentence such as "I don't know why". However, you have to rephrase that sentence a little: