This table shows what class each Hebrew letter falls into. The mother letters are the beginning, middle, and end of the Alef-Bet[1]. The double letters each have two sounds, hard and soft. The simple letters have only one sound (though each may represent one of several English letters when transliterated).

Letter Mother Double Simple
א Alef Y
ב Bet Y
ג Gimel Y
ד Daleth Y
ה Heh Y
ו Vau Y
ז Zain Y
ח Cheth Y
ט Teth Y
י Yod Y
ך כ Kaph Y
ל Lamed Y
ם מ Mem Y
ן נ Nun Y
ס Samekh Y
ע Ayin Y
ף פ Peh Y
ץ צ Tzaddi Y
ק Qoph Y
ר Resh Y
שin Shin Y
ת Tau Y

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Alef-Bet | mother letters | double letters | simple letters

[1]The actual last letter, ת (Tau), doesn't count as a mother because it is a double.
[1]The actual last letter, ת (Tau), doesn't count as a mother because it is a double.