Hello,
I've just started to learn Biblical Greek and am currently looking at the reduplication in completed aspect verbs. Our lecturer mentioned different ways of reduplication: adding the initial consonant and e, adding just an e when the verbal stem begins with a vowel/dipthong, an initial sibilant or two initial consonants where the second is a liquid, and something called attic reduplication.
Two questions: is 's' the only sibilant in koine Greek? Secondly, what is attic reduplication?! Thanks in advance for any help... .

