is the most common pronunciation of the infamous यह and वह maybe closer to phonetic as यह् and वह् ?
that little mark is the key i use to make a ligature indicating no vowel in between...
e.g. हिन्दी = ह ि न ् द ी
and i think i see it on the end of an alt spelling of"Sanskrit" संस्कृतम्
i'm not saying they should be spelled that way, e.g. English spelling doesn't say wimen [women], foto [photo], cof [cough], etc.
i'm just wondering if i understand what that ् mark means, and how one most commonly says वह and यह ?
though possibly it should be वेेह ?
In their most basic form, every consonant in the Devanagari script is attached to the vowel अ. The ् diacritic (called 'halant' in Hindi) is used to delete this innate vowel. So, क is 'ka' while क् would be 'k'.
As bhavishyab7 says, the halant is used much more commonly in Sanskrit than in Hindi.
This is because in Sanskrit, the vowel अ that is attached to a consonant is always pronounced unless it is explicitly cancelled by the halant. For example, my name विनय would be pronounced 'vinaya' in Sanskrit, the script name देवनागरी would be pronounced 'devanaagari' etc.
However, in Hindi, the अ vowel is always deleted in pronunciation when it occurs at the end of a word and also sometimes in the middle of a word (a phenomenon called 'schwa deletion'). So, विनय is pronounced 'vinay', संस्कृतम is pronounced 'sanskritam' even without the halant, देवनागरी is pronounced 'devnaagri' instead of 'devanaagari' etc. As a result, Hindi doesn't have as much use for the halant.
Therefore, even without the halant, if यह and वह were to be pronounced as they are written, they would be 'yah' and 'vah'. However, the most common pronunciation is actually closer to 'yeh' and 'voh'.
This has little to do with schwa deletion and is more because of the letter ह which tends to mess with phonetic pronunciation in Hindi when it occurs in the middle or end of a word. Other examples include छह (six) pronounced 'cheh', बहन (sister) pronounced 'behen', बहुत (many) pronounced 'bohot', महल (palace) pronounced 'mehel' etc.
That is a tricky example. The metathesis of letters in conjugations of ह with a nasal consonant occurred pretty long ago in Sanskrit itself. So, ब्रह्म would be commonly pronounced non-phonetically as ब्र+म्+ह (even though it is written ब्र+ह्+म) in practically all modern Indian languages and even by quite a few Sanskrit scholars.