The ו החיבור rules 1. In general it is "ve" 2. In 2 case it is "u" * before the letters בומפ (the leaps letters) because "ve" is also with the leaps * befre letters with שווא (shva) like שְתיה קְרובים צְבי 3. Before יְ (yud + shva) it is "vi", eg: יְרושלים יְרוקה יְהודה יְלדים (yerushalaim => virushalaim, yeruka => viruka) 4. In the Bible and the Mishna there are circumnstances when it is "va", but in modern Hebrew it is used only in specific cases: before the numbers שש שבע תשע חצי רבע (eg עשרים וָשש or שמונה וָרבע) and in specific expressions from the Bible and the Mishna like בשר וָדם.

The Hebrew "and" can be ve/va/u/vi (4 options), but as Or Raveh said - most of the native Hebrew speakers don't care too much about it , and I accept his recommendation.. If you really want to know the rules - let me know.. I don't know why the י of עכשיו is not pronounced, but note that it happens in many other words: עכשיו, סתיו and in conjugated nouns (third person singular + noun plural) - ידיו, נעליו, עליו..

About "עכשיו" and the like: the YUD is there only when we write the word without NIKUD. The added YUD is silent (it isn't pronounced as an "a" - it isn't pronounced at all), and its role is to prevent us from mistakenly reading the word as ACHSHU / ACHSHO. The YUD is doing it by creating a space between the SHIN and the VAV.

Thank you, Or!

I don't know the answer, but I can say that although it's probably wrong, most people mainly use "ve".