The Hebrew word for "letter" is "aw-t" אות but this is also the Hebrew word meaning a "sign" from God. It is the word used in Gen. 9:17 where we are told that the rainbow was a "sign" and it is used in Exod. 31:17 where the sabbath is called a "sign". So in fact we need to consider that the Hebrew "letters" are more than just letters they are "signs" from God.
Note: Paleo Hebrew was essentially the Phoenician alphabet that added semantic meaning through the novel use of dual=purpose "vowel letters" (i.e., Aleph, Hey, Vav). this script was used during the First Temple Period (though it was also used as a symbol of nationalistic revival in the Second Temple Period. A modified version of this script (Samaritan) is still extant today.
Also note that the 6th Hebrew Letter "Vav" (in Modern Hebrew) was called "Wow" in Biblical times which is why it can also make the "w" sound. Also the modern Hebrew final letter "Tov" in Biblical times was called "Tau".
In Genesis 1:1 in the English we read, "In the beginning God created the Heavens and the Earth." In the Hebrew it reads "beresheet bara elohim et hashamiyim vet haarets". The word "et" is not a translatable word here it is a grammatical direction used to connect the definite object (the Heavens) to the elohim. This word "et" is spelled in Hebrew with the first and last letters of the Hebrew Alephbet, an Aleph and a Tov. We are told in the scriptures that God spoke the creation into existence so many Rabbis feel that in order to speak creation into existence there would first have to be a language so this little word "et" in Genesis 1:1 give just before mentioning the creation of the Heavens and the Earth signifies the creation of the Hebrew Alephbet, Aleph to Tov. The interesting thing is at the end of each Stage in Creation God summarized it in Genesis 1 as being "good"; I find it interesting that the last letter of the Modern (completed) Hebrew Alephbet is "Tov" which means "good". Is this too a summary from God in regards to His created letter system?
Here are the Hebrew Vowels in the Niqqud with the name of each vowel and the corresponding sound it makes.
Other Diacritic symbols include:
Degesh - This is the dot placed in the center of the letter bet or kaph in order to show one of the letter's two sounds. In modern Hebrew the 3 degesh letters are "Bet", "Kaph", and "Pey"; but in Ancient Hebrew there were 6 degesh letters which were the 3 modern degesh letters plus "Gimel", Dalet", and Tov". When learning Ancient Hebrew an acronym is used to remember these letters. They are called the "Bagadkphat" letters which stands for B.G.D.K.P.T. In the Ancient Hebrew the Gimel could make a hard "G" sound or a soft "J" sound; the Dalet could make a hard "D" sound or a softer "DH" sound; and, the Tov which was then called Tau could make a hard "T" sound or a soft "TH" sound.
Mappiq - This is the dot placed in the center of a letter to express that it is a consonant sound and not a vowel - for instances it is placed in the center of the letter "hey" in order to express an "h" sound instead of the usual vowel sound "ah".
Rafe - This is a small line above letters and is to direct the reader to create a sound like pushing air through your lips when they are tight to your teeth for instant making a "p" sound more like and "f".
Maqaf - Is the Hebrew name for a hypen. Used basically the same as it used in the English. But rarely is any punctuation used in the Hebrew.
Hebrew Prefixes and Suffixes:
Here are the 10 Commandments (in Hebrew "the 10 Sayings") from Exodus 20 In 4 different Language periods:
Proto-Sinaitic (Early) Hebrew
Paleo (Middle) Hebrew
Late Hebrew - (Dead Sea Scrolls)
Modern Square Script Hebrew
Greek Alphabet Charts:
Note: One form of Gematria is to give the final or "soffit" letter forms their own value as per the chart above. Other more common forms of Gematria assign the same numerical value to the 5 soffit forms as the corresponding non-soffit form letters.