deriv SD cv (298) ashtadhyayi.com hei.de L 298 ETT STT a 7.2.108 ALPH OLDHOMEPAGE NEWHOMEPAGE

idamo maH इदमो मः ONPANINI 72108

/idam- keeps its m म् (before /su).

This is an exception to <6 tyadAdInAmaH, which would make ida इद before /su.

/idam- m + /su → **ayam अयम्

/idam- f + /su → **iyam इयम्

The neuter is **idam इदम्.

Can you translate the sUtra word for word please?

Literally —

Replace /idam- with m म् (before /su).

idamas इदमस् means "replace idam इदम्"

mas मस् means "with m म्"

As there is no /zit in ma म, like in /zI, this replaces only the last letter, turning /idam- into idam- इदम्, which is an exception to the change of /idam- into ida- इदॱ by <6 tyadAdInAmaH.