Many Christians pronounce the Name of God as "Jehovah." However, though it is debatable, most scholars agree that the proper pronunciation is "Yahweh." Now, what I am referring to is not the full Name of God, because the full name of God is not known. Because of the Commandment which says "Thou shalt not take the Name of the Lord God in vain," the Hebrews, afraid of accidentally breaking this commandment, took out the vowels, so that His proper Name could not be accidentally pronounced in an unholy manner. The result, 'YHWH,' is called a 'Tetragrammaton.'
"Various proposals exist for what the vowels of יהוה were. Current convention is יַהְוֶה, that is, "Yahweh" (IPA: [jahˈweh]). Evidence is:
* Some Biblical theophoric names end in -ia(h) or -yahu as shortened forms of YHWH: that points to the first vowel being "a".
* Various Early Christian Greek transcriptions of the Hebrew Divine Name seem to point to "Yahweh" or similar.
* Samaritan priests have preserved a liturgical pronunciation "Yahwe" or "Yahwa" to the present day.
Today many scholars accept this proposal, based on the pronunciation conserved both by the Church Fathers (as noted above) and by the Samaritans. (Here 'accept' does not necessarily mean that they actually believe that it describes the truth, but rather that among the many vocalizations that have been proposed, none is clearly superior. That is, 'Yahweh' is the scholarly convention, rather than the scholarly consensus.) In some editions of the sidur, Jewish prayer book, there are no vowels under God's name, to signify that we do not know God's name and that there is absolutely no pronunciation."
"Hebrew Scholars generally favor "Yahweh" as the most likely pronunciation. They point out that the abbreviated form of the name is Yah (Jah in the Latinized form), as at Psalm 89:8 and in the expression Hallelu-Yah (meaning "Praise Yah, you people!") (Ps 104:35; 150:1,6). Also, the forms Yehoh', Yoh, Yah, and Ya'hu, found in the Hebrew spelling of the names of Jehoshaphat, Joshaphat, Shephatiah, and others, can all be derived from Yahweh. ... Still, there is by no means unanimity among scholars on the subject, some favoring yet other pronunciations, such as "Yahuwa", "Yahuah", or "Yehuah"."
"Traditionally, observant Jews do not say this name aloud. It is believed to be too sacred to be uttered and is often referred to as the Ineffable Name, the Unutterable Name or the Distinctive Name. They often use circumlocutions when referring to the name of the Deity, e.g., HaShem ("The Name") or Shem HaMeforash (“the ineffable Name”) when reading the Tanakh aloud because the Name of God must not be spoken. They show such reverence because of how holy God's Name is and they do not want to ever give off the impression that they are misusing or taking the Lord's Name in vain. "Adonai" is spoken only in prayer, and YHVH is only written on paper that will not be thrown away or discarded. Adding vowels to the Name of the Lord is an insult to some Jews because the point is that it cannot be spoken because it is God's Name (to be). Even in English the vowel in God (G-d) is taken out in some cases to show extreme reverence. Even some Christians follow these traditions in order to stray from seeming irreverent to God."
"Using consonants as semi-vowels (v/w)
In ancient Hebrew, the letter ו, known to modern Hebrew speakers as vav, was a semivowel /w/ (as in English, not as in German) rather than a letter v. The letter is referred to as waw in the academic world. Because the ancient pronunciation differs from the modern pronunciation, it is common today to represent יהוה as YHWH rather than YHVH.
In Biblical Hebrew, most vowels are not written and the rest are written only ambiguously, as the vowel letters double as consonants (similar to the Latin use of V to indicate both U and V)."
"For similar reasons, an appearance of the Tetragrammaton in ancient Egyptian records of the 13th century BC sheds no light on the original pronunciation. Therefore it is, in general, difficult to deduce how a word is pronounced from its spelling only, and the Tetragrammaton is a particular example: two of its letters can serve as vowels, and two are vocalic place-holders, which are not pronounced.
This difficulty occurs somewhat also in Greek when transcribing Hebrew words, because of Greek's lack of a letter for consonant 'y' and (since loss of the digamma) of a letter for "w", forcing the Hebrew consonants yod and waw to be transcribed into Greek as vowels. Also, non-initial 'h' caused difficulty for Greeks and was liable to be omitted; х (chi) was pronounced as 'k' + 'h' (as in modern Hindi "lakh") and could not be used to spell 'h' as in e.g. Modern Greek Χάρρι = "Harry"."
"Kethib and Qere and Qere perpetuum
The original consonantal text of the Hebrew Bible was provided with vowel marks by the Masoretes to assist reading. In places where the consonants of the text to be read (the Qere) differed from the consonants of the written text (the Kethib), they wrote the Qere in the margin as a note showing what was to be read. In such a case the vowels of the Qere were written on the Kethib. For a few very frequent words the marginal note was omitted: this is called Q're perpetuum.
One of these frequent cases was God's name, that should not be pronounced, but read as "Adonai" ("My Lord [plural of majesty]"), or, if the previous or next word already was "Adonai", or "Adoni" ("My Lord"), as "Elohim" ("God"). This combination produces יְהֹוָה and יֱהֹוִה respectively, non-words that would spell "yehovah" and "yehovih" respectively.
The oldest manuscripts of the Hebrew Bible, such as the Aleppo Codex and the Codex Leningradensis mostly write יְהוָה (yehvah), with no pointing on the first H; this points to its Qere being 'Shema', which is Aramaic for "the Name".
Gerard Gertoux wrote that in the Leningrad Codex of 1008-1010, the Masoretes used 7 different vowel pointings [i.e. 7 different Q're's] for YHWH.
Later, Christian Europeans who did not know about the Q're perpetuum custom took these spellings at face value, producing the form "Jehovah" and spelling variants of it. The Catholic Encyclopedia [1913, Vol. VIII, p. 329] states: “Jehovah, the proper name of God in the Old Testament."