List conjunctions link or contrast nouns and adjectives. They do not cause initial consonant mutations and do not have to agree with the other words in gender.
Clause conjunctions link clauses in a sentence. Because standard word order is VSO, these conjunctions often immediately precede a verb, but because indirect objects are allowed before the verb, they don't always. When a clause conjunction is followed by an indirect object, it acts like a list conjunction, i.e. it does not not cause mutations and does not have to agree with other words in gender. When it precedes a verb though, it acts like a preposition to the verb, including causing lenition and agreeing with the verb in gender where appropriate.
as so, that, such that, therefor (introduces a general subordinate clause)