Reason for different punctuation of the prefix vav?

Question

In the Siddur, the prefix vav is seen with various punctuations (e.g., shva, kamatz, patah, shuruk). When is each of these different punctuations used with a prefix vav and how does each affect the meaning of the prefix vav?

Answer 1

In biblical Hebrew:

• When preceding an imperfect (future-form) verb to make it past tense, the vav has a patach.
• However, that patach becomes a kamatz before an alef.
• Otherwise, when the word is the last in a phrase and has its stress on the syllable after the prefixed vav, that vav has a kamatz.
• If none of the above apply, the prefix has a sh'va, except that that sh'va changes to:
  • a patach if it's preceding a word that starts with a guttural chataf patach
  • a kamatz if it's preceding a word that starts with a chataf kamatz
  • a tzere or sometimes segol if it's preceding a word that starts with an alef-chataf segol
  • a segol if it's preceding a word that starts with a chataf segol (not on an alef)
  • a chirik if it's preceding a word that starts with a yod-sh'va
  • make the vav a shuruk if it's preceding a word that starts with a sh'va (not on a yod)
  • make the vav a shuruk if it's preceding a word that starts with the letter bes, mem, pe, or vav

Most of these rules can be found in Gesenius §104, which states them more precisely and also gives examples.

The sidur follows the above rules when quoting biblical passages. It strays in some ways from biblical grammar in more modern parts of the sidur, but — and this is just my impression — I don't think that the above rules of how to punctuate vav are among those strayings.