The usual practice in roman script is to separate the two vowels with a space, showing that they are not a diphthong but belong to two different syllables. E.g.

manaḥ + indriya- = mana indriya-

I don't think that looks strange. You can see it for instance in Edgerton's Bhagavadgita (Harvard U. Press, 1952) ch 2 verse 9c: na yotsya iti govindam (na + yotsye + iti).

By the way, what distinguishes the separate vowels from the diphthong in nagari is not the space (which isn't always marked in manuscripts) but the fact that the second vowel (in your case the i) is written with a character, not with a stroke added to a consonant character. This makes a space possible, though not necessary. Indeed, such hiatus can occur within a word, which is rare in Sanskrit (e.g. pra'uga "the forepart of the shafts of a chariot; triangle"), but common in Prakrit. Here, it would be very odd to write a space, since it's within a word. I've marked the hiatus with an apostrophe, but Monier-Williams does it with diaeresis/tréma (two superscript dots).

I hope that solves your doubts quicker than Arjuna's.

On 27 Apr 2016 at 10:59, Christophe Vielle wrote:

is there a way in Roman script for distinguishing in a compound the result of - aḥ + vowel other than a which could be i = a i, with hiatus, from the diphthong ai resulting from a/ā + e/ai ?

ex. manaḥ + indriya- = manaindrya- (?) beside mānasa + aindriya = mānasaindriya

In nâgarî script I find written mana indrya- with a space put between the two members, but it would look strange in Roman script.

Any suggestion welcome.

Newcastle upon Tyne NE3 1XT

Phone (0191) 285 8053