How to use a clause/phrase like "prep.+which+do"? FIRST ONE:The Achaemenid empire of Persia reached the Indus Valley in the fifth century B.C., bringing with it the Aramaic script, 【from which derive】 both the northern and the southern Indian alphabets. I know the clause can be understood as "both the northern and the southern Indian alphabets derive from which". SECOND ONE:Based on records from ancient Athens, each year young Athenian women had collaborated to weave a new woolen robe 【with which to dress】a statue of the goddess Athena and that this robe depicted scenes of a battle between Zeus, Athena's father, and giants. This is a wrong sentence, but I just wanna know whether its usage of "prep.+which+do" is correct? Or shall I change it to "a new woolen robe with which had been dressed"? And in this way, can I comprehend this clause as "a statue of the goddess Athena had been dressed with a new woolen robe"? If it's possible, please make a further explanation of "prep.+which+do" usage. Thank you in advance.Hi everyone, thx for clicking in this question. I'm confused about the usage of "prep.+which+do" and I hope someone can clarify the usage of this phrase. I got two examples here. Thanks again.