KAF (כ):
Eleventh letter of the Hebrew alphabet. The name is generally taken to mean "hollow of the hand," to which the shape of the letter has a near resemblance (see Alphabet). Kaf belongs to the six consonants called "mutes," and has a twofold pronunciation: an explosive, which is indicated by the "dagesh lene" placed in the middle of the letter, and a spirant. In the former case it corresponds to the English "k," and in the latter nearly to the Greek χ (by which it is often represented in Greek transliteration) or the German soft "ch" (there is no English equivalent). As a palatal kaf is related to נ and ק, with which it sometimes interchanges; in some rare cases it passes into the harsh gutturals ח and ע. The syllable "ke" () is a preposition, meaning "at," "as," and is prefixed to nouns and infinitives. At the end of a word kaf is written thus: ד. When used as a numeral it has the value for 20.