Could someone please, very directly, say what the differences are between Yahweh, Adoni, Elohim and Jehovah and the word God?
Yahweh is a rendering of this:
Which has no known meaning or pronounciation at this time, due to those who did are gone (the High Priests).
Adoni means "Lord".
Elohim refers to the divine, and is plural (a reference to the Trinity). It is superficially similiar to El, which means "god" (in a generic way just like the Germanic "god", but it specifically used to refer to God when used in the True Faith)
The word "God" is germanic, meaning "god" but used in a specific way. Many languages have a word which means something which can be used to describe God. A language like Hindi has many names for "god", however, they are highly specific at times (it would be inappropriate to translate "In the beginning God created heaven, and earth." using "Vishnu" for "God" because Vishnu refers to a specific entity by its nature). A word like परमेश्वर can be used to refer to "God" because it is more vague and dependent on the understanding of the reader.
Jehova is a result of the transliteration of יהוה
Because it was going from a Semitic to Greek to Latin alphabet, the letters changed.
Semitic abjads do not have vowels, so the transliteration of יהוה to a Latin alphabet is "YHWH" (Semitic languages are formed differently and the lack of vowels is not so important, for native speakers, as words are formed with consonental roots). Because of the transliteration of it into a Latin script, it was subject to changes due to differences in languages. So for a Greek, "יהוה" sometimes came out Ιουώ, or Ιεού, and it going into a Latin script would be equally different. Since it was written, and how it was said was not know, and the fact that there are morphological differences in Hebrew, Greek, Latin and English, its pronounciation is highly dependent on its spelling and the individuals understanding of it. "Yaweh" as an English speaker would say it is more like how it could be said in Hebrew. "Jehova" as an English speaker would say it, is not Hebrew like at all.